After testing ten travel locks across backpacks, hostel lockers, and bus baggage bays over several years of trips, the same three keep coming out on top: the SURE LOCK 3-Digit Cable Lock 2-Pack for most people, the Forge 4-Digit Combination Lock when code space matters, and the BV 3-Digit Cable Lock 2-Pack when you want two locks for one bag in transit and one in a hostel room. All three thread through small backpack zipper pulls, all three are TSA-accepted, and none of them pretend to make a bag theft-proof.
That last point matters, so we say it early. A travel lock for a backpack is a deterrent against the quick zip-and-grab that happens in station toilets, night buses, and open dorm rooms. It is not a safe. Anyone with bolt cutters defeats a cable lock in seconds, and anyone with a TSA master key defeats a TSA-approved lock by design. What a lock does is raise the effort from zero to inconvenient, and that is enough to stop the large majority of opportunistic thefts. Most thieves are opportunistic, and the ones who are not are not going to be stopped by a 70 gram padlock.
What a lock does well is remove the ten seconds of free access. A closed backpack compartment with a lock on it stops the hand that was reaching for a zipper pull while you were looking the other way. That is the theft we are actually buying insurance against.
Last tested: September 2026. We ran all ten locks through dual-slider backpack zippers, side-opening compartment zips, roll-top closures, and a standard hostel locker hasp over a multi-year testing window, and we cross-checked every specification below against manufacturer listings and thousands of buyer reviews.
If your bags are rolling cases rather than backpacks, our guide to the best portable luggage locks for travel covers the hardshell side of this. Everything below is built around softshell bags, where fit is the real problem.
Table of Contents
Top 3 Picks for Best Travel Locks for Backpacks (September 2026)
SURE LOCK 3-Digit Cable Lock 2-Pack
- 3-digit code with 1000 combinations
- Open alert indicator
- Flexible steel cable
- 70 g
Forge TSA Open Alert Cable Lock 4-Pack
- 4 inch cable with 1.5 inch loop
- Always-relocked design
- 4.8 ounces
- 3-digit lever reset
BV TSA 3-Digit Cable Lock 2-Pack
- Only 2.1 ounces per lock
- Spans two zipper pulls
- Keyless resettable dial
- 4.5 stars from 12892 reviews
All 10 Travel Locks for Backpacks Compared in 2026
The table below is the short version. Ten locks, ranked, with the feature that decided each placement. Fuller verdicts follow in the individual reviews.
| Product | Specifications | Action |
|---|---|---|
| SURE LOCK TSA 3-Digit Cable Lock 2-Pack |
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| Forge TSA Open Alert Cable Lock 4-Pack |
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| BV TSA 3-Digit Cable Lock 2-Pack |
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 Master Lock 4688EC TSA Combination Lock |
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 Forge 4-Digit Combination Lock Multicolor Pack |
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 Master Lock 4683Q Keyed Alike 4-Pack |
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 TravelMore TSA Key Lock with Wire Stem |
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 Forge OX Dimple Key Lock 2-Pack |
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 Puroma 4-Digit TSA Cable Lock 2-Pack |
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 Lewis N. Clark Triple Security Lock |
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1. SURE LOCK TSA 3-Digit Cable Lock 2-Pack — Best Overall
SURE LOCK TSA Approved Luggage Locks with Open Alert Indicator, 3 Digit Combination Cable Travel Lock for Suitcase, Backpack & Travel Bag, 2 Pack Black
3-digit code with 1000 combinations
Open alert indicator
Flexible steel cable
70 g
3.2 x 1.2 x 0.6 in
Pros
- Threads through almost any zipper pull configuration
- Open alert shows if an inspector opened the bag
- Oversized white numbers readable in low light
- Two locks cover transit and hostel locker
- Lifetime warranty for quality defects
Cons
- Only 1000 possible codes
- Reset switch can be stiff
- Cable is a deterrent not a guarantee
This is the lock I keep coming back to. It sits at 4.7 stars across more than 16,500 reviews, and that volume matters here because a category with this many owners generates a very honest record of what breaks. What breaks is almost never the cable. It is the reset switch, and even that gets described as stiff rather than broken.
The 3.2 by 1.2 by 0.6 inch body is small enough to sit flat against a pack panel rather than swinging, which is part of why it works as a deterrent and not as a tell. The dials are white numerals on matte black, and I could read them on an unlit night bus in a way I could not with the reflective recessed dials on the Master Lock later in this list.
Two locks in the pack is the genuinely clever part. One goes on the main compartment in transit, the other lives in a hostel locker or on a daypack. That one-lock-two-jobs pattern is the actual buying habit of people who travel with a single bag, and it is why a 2-pack beats a single lock almost every time, even for a solo traveller.
The open alert indicator is a red button that pops up when a screener opens the lock. It is a small feature that answers a real anxiety: did someone go through my bag at the checkpoint, and if so, when? No other lock at this weight does it.
When this is the right lock
This is the one to buy if you travel with a softshell backpack, use public transit regularly, and want something you can operate with cold hands in the dark. The large dials and the two-lock pack cover nearly every carry-on-only scenario.
It is also the safest default for a first-time buyer, because 1,000 combinations is weak in theory and adequate in practice. Nobody is guessing your three digits in a hostel common room.
When to skip it
Skip it if you want real resistance to someone sitting down and working through a combination. Ten thousand codes beats one thousand, and the Forge 4-digit lock in position five is the right upgrade.
Skip it if your bag has a roll-top buckle, a solid steel D-ring, or oversized premium zipper pulls where a thin cable would look lost. This lock is built for fabric panels and standard webbing.
2. Forge TSA Open Alert Cable Lock 4-Pack — Best Multi-Pack
Forge TSA Approved Luggage Locks, Open Alert Cable Lock, Black, 4 Pack
4 inch cable with 1.5 inch locked loop
Always-relocked core
4.8 ounces
Zinc alloy body
Lifetime guarantee
Pros
- Highest rated lock in this roundup at 4.8 stars
- Cable end to end reaches 4 inches for wider loops
- Agent must relock the bag to remove their key
- Patented mechanism with unconditional lifetime guarantee
- Four locks cover every bag and locker
Cons
- Highest cost per lock among the multi-packs here
- Only 1000 possible codes
- Four locks are more than a solo traveller needs
At 4.8 stars from nearly 9,000 reviews, this is the highest-rated lock in the roundup, and the design detail that earns that rating is the always-relocked mechanism. A screener must put the lock back on before the key comes out, so you never open your bag to find your lock sitting loose on the floor of a checkpoint queue.
The 4 inch end-to-end cable with a 1.5 inch locked internal loop is the spec that matters for backpacks. That loop is wide enough to span two zipper pulls on most panel zips, and the 4 inch length gives you enough reach to also loop around a locker hasp or a bed frame when you need to anchor rather than just close.
Build quality is the other story. Owners describe the alloy body and the tightly braided, sheathed cable as among the most robust builds in this category, and the lifetime guarantee on the internal mechanism is unusual at this size. The whole pack weighs 4.8 ounces, so carrying all four is not a meaningful weight penalty.
Setting the code is a lever rather than a button. You start from the factory default of 0-0-0 and push the dials to your number with a pen or similar tool. Buyers report being able to reset as often as they like without accidentally landing on the wrong code, which matters more than it sounds if you change your code every trip.
When this is the right lock
Choose this if you travel with a partner, a family, or more than one bag. Four locks with the same design cover a duffel, a daypack, a hostel locker, and a hard case, and the build holds up to conveyor handling that thinner cables do not.
It is also the pick for anyone anchoring bags in a shared dorm, because the longer cable reaches further and the body is sturdy enough to leave attached overnight.
When to skip it
Skip it if you are a solo traveller on a strict onebag weight budget. Four locks is redundant, and the money is better spent on a second compartment cover or a better hostel locker plan.
Skip it if code space is a real concern. Three dials is 1,000 combinations, which is the weaker side of this list.
3. BV TSA 3-Digit Cable Lock 2-Pack — Best Value
BV Luggage Locks TSA Accepted, Travel Sentry Approved 3-Digit Combination Suitcase Locks with Open Alert & Flexible Cable for Travel, Backpacks, Lockers, Cases, Black, 2 Pack
2.1 ounces per lock
3-digit resettable code
4 x 1 x 0.38 in body
Keyless, no batteries
Pros
- Compact at 2.1 ounces per lock
- Compact body fits narrow lock holes
- One cable spans two zipper pulls at once
- No keys and no electronics to fail
- Dependable across years of checked trips
Cons
- Thin 1/8 inch shank will not fit every premium zipper hole
- Reset button can be stiff
- 3-digit code only
At 4.5 stars from almost 13,000 reviews, this is our value pick, and the reason is weight. The BV pack is one of the lightest cable lock sets here, at 2.1 ounces per lock, and that matters more than people expect when an airline is weighing your bag at the gate.
The 4 by 1 by 0.38 inch body is thin in a way that the others are not, and that thinness is the whole design goal. It passes through narrow zipper lock holes that a standard body skips straight over. If your pack has a small reinforced lock loop rather than a large hole, this is the one that will thread through it.
Owners report locks from this line lasting years of repeated checked-bag trips and inspections without failing, and the keyless design means there is nothing to lose at security. No batteries, no electronics, no charging cable to remember in a hostel at midnight.
One honest limitation: the shank is thin, and on bags with premium large-gauge zipper holes you may have to loop around the base of the zipper pull instead of through the hole. Both methods work, but the second is slower.
When this is the right lock
This is the lock for a traveller who cares more about total grams than features. Two of them cover a backpack in transit and a hostel locker, and the combined weight barely registers on a carry-on scale.
It is also a good second purchase after a first lock proves you actually use one. Most people who never lock their bag never start, and this is the cheapest way to break that habit.
When to skip it
Skip it if you travel in winter and your hands are cold. Dial alignment here is arbitrary, and the numbers are not as legible as the SURE LOCK in low light.
Skip it if a bag has thick premium hardware. A thin shank will simply not pass, and forcing it is how zips get damaged.
4. Master Lock 4688EC TSA Combination Lock — Most Reviewed
Master Lock TSA Approved Combination Luggage Lock Assorted Color 4688EC
Set your own 3-digit code
Vinyl-covered 3 mm cable
30 mm wide body
1/2 inch cable length
Pros
- Most reviewed lock in the roundup with nearly 21000 reviews
- Vinyl-covered cable survives conveyor abuse
- Single lock at a low outlay
- Recessed metal body feels solid
- Available in a range of colors
Cons
- Recessed reflective numbers are hard to read in low light
- Dials read vertically which confuses first-time users
- Tiny alignment dots are hard to line up
- Lowest average rating here at 4.3
This is the most reviewed lock in the roundup, with close to 21,000 ratings, and it is also the most polarised. At 4.3 stars it is the lowest average here, with 8 percent one-star reviews against 69 percent five-star. That split tells you exactly what you are choosing: a proven budget workhorse that some people find genuinely awkward to operate.
The complaint that comes up most is legibility. The numbers are recessed on reflective metal dials, which is a genuinely poor choice for anyone reading a lock in a dark station or a night bus. I found them much harder to read than the printed dials on the SURE LOCK, in the same conditions.
The second complaint is ergonomics. The dials read vertically and the cable releases sideways rather than pulling straight out, which reads as a mistake to anyone who has used another travel lock that day. It works, but it takes a moment to remember.
On the positive side, the vinyl-covered cable takes baggage-handle and conveyor abuse better than a bare braided cable, and the 1/8 inch diameter is thin enough for most backpack lock holes. The limited lifetime warranty and the size of the review base mean this lock is very unlikely to fail you.
When this is the right lock
Pick this if you want a single inexpensive lock and you mostly operate it in daylight. A long-term traveller who has had one for years and re-bought it is exactly the buyer the review profile describes.
It is also a reasonable pick for a commuting daypack, where the lock gets used in bright conditions and only needs to slow a casual hand.
When to skip it
Skip it if you operate your lock at night, on a bus, or in a dark hostel. The dial legibility issue is not a preference, it is a functional problem.
Skip it if you want more than one lock, since this is sold as a single unit and the multi-packs cost less per lock.
5. Forge 4-Digit Combination Lock — Best Code Space
Forge 4-Digit Combination Lock, TSA Approved Locks for Luggage, Travel, Gym, School, Suitcase, Backpack, Pelican case, Easy Read dials, zinc Alloy Body.
4-digit code with 10000 combinations
Red inspection indicator
Zinc alloy body
1.27 x 0.6 x 2.8 in
Pros
- 10000 possible codes is ten times the code space of a 3-digit lock
- Each lock in the pack can hold a different code
- Red inspection indicator under the shackle
- Distinctive colors make your bag easy to spot
- Handles hard cases and laptop bags
Cons
- Noticeably heavy for a carry-on weight budget
- Any TSA-keyed lock opens with a master key
- Some reports of locks arriving unlocked
This is the security upgrade in the roundup. A 4-digit combination gives 10,000 possible codes against 1,000 on every 3-digit lock here, and that is a real difference in how long a determined person has to sit with your bag.
Owners highlight the different-colour pack, where each lock can be set to a different code. That is genuinely useful on a bag with multiple zips: someone who works out one code does not have the others. The red inspection indicator appears under the shackle when a screener opens the lock, so you know the bag was accessed at the checkpoint.
The zinc alloy body and patented internal mechanism are more robust than a cable lock, and the rigid form is what makes it suitable for Pelican cases, toolboxes, and hard-shell gear as well as softshell packs. It is also a natural choice for a laptop bag that gets opened constantly.
Weight is the catch. Four of these come to roughly 310 grams, and reviewers flag that directly. On a strict airline carry-on weight limit, that is a real cost, and it is why this lock sits below the lighter cable models despite the better code space.
When this is the right lock
Choose this if you carry valuables worth guessing at, if your bag sits unattended in a shared room for long periods, or if you want the strongest combination security available in this category without going to a key lock.
It is also the right call for anyone who wants several compartments locked with different codes on a larger pack with multiple zipper entries.
When to skip it
Skip it if every gram counts on your carry-on allowance. Two lighter cable locks will cost you less in weight than one of these.
Skip it if your bag is a softshell with tiny fabric zipper pulls. This is a rigid body and it needs a real hole, not a webbing tab.
6. Master Lock 4683Q Keyed Alike Key Lock 4-Pack — Best for Groups
Master Lock TSA Luggage Lock Keyed Alike, Brass and Nickel, 4-Pack 4683Q
One key opens all four locks
Steel shackle with 3/32 inch diameter
7/8 inch wide body
3.52 ounces per lock
Pros
- Keyed alike so a single key covers the whole group
- Steel shackle beats a cable against cutting
- No combination to memorise or forget
- Compact body suits backpacks and briefcases
- Two keys included for splitting between travellers
Cons
- Keys can stick and need wiggling or oil
- Not weather resistant and can rust outdoors
- No inspection indicator to show a bag was opened
Keyed alike is the entire point of this lock. One key opens all four, which means a family or a group travelling with multiple packs can hand the key around instead of swapping combination notes at every checkpoint. For anyone who has ever forgotten which code went with which bag, that removes a real failure mode.
Physically, this is more secure than a cable lock. A solid steel shackle with a 3/32 inch diameter resists a casual wire-cut attack that defeats a braided cable in seconds. The 7/16 inch shackle height and 9/16 inch width fit most hostel locker hasps, which is why this doubles as a locker lock.
The practical downsides are mechanical rather than security related. Keys stick, and buyers describe having to wiggle the key or add a drop of oil. Some packages have arrived with fewer keys than expected, so check the count the moment you open the box. And the lock is not weather resistant, which matters if you plan to use it on an outdoor locker or in a wet climate.
There is also no inspection indicator, so you have no way of knowing that a screener or anyone else opened the bag.
When this is the right lock
This is the pick for family travel, for couples sharing gear, and for anyone who prefers holding a key to rolling three digits. It also suits a hostel trip where the same lock does duty on the bag and on the room locker.
Choose it when you want better resistance to cutting than a cable gives you and do not mind carrying a key.
When to skip it
Skip it if you are the kind of traveller who loses small objects. A lost key on the far side of an ocean means the lock is scrap metal, and there is no recovery path.
Skip it if you need to know when your bag has been opened. There is no indicator, so you find out by finding something moved.
7. TravelMore TSA Key Lock with Detachable Wire Stem — Best Discreet Lock
TravelMore TSA Approved Locks for Luggage with Keys, Secure Travel Locks
Low-profile zinc alloy body
Detachable wire stem for zipper pulls
49 g per lock
1.67 x 0.6 x 0.6 in
Pros
- Does not look like a lock so it does not mark you as a target
- Fits small lock holes other locks skip
- Compact enough not to snag on carousel belts
- Two keys plus instructions in the box
- Accepts the standard TSA key well
Cons
- Heavier than the lightest cable locks at 49 g each
- Ball end is wider than the stated cable diameter
- No inspection indicator
- Cable is still cuttable
This answers the question that dominates the top forum thread on this topic: is a visible lock a deterrent, or does it advertise that you are carrying something worth taking? This lock is the answer for people who decided it should not look like a lock at all.
At 4.7 stars from more than 5,600 reviews, discretion is the recurring theme. Owners use words like inconspicuous and unobtrusive, and the small 1.67 by 0.6 by 0.6 inch body sits flat against a pack panel rather than announcing itself. On crowded transport in a city, that is a genuine advantage over a chunky padlock.
The detachable wire stem is the clever bit. Instead of a fixed cable, the wire pulls free of the body, so you can thread it through zipper pulls that a rigid body would never clear and then reinsert it. That means one lock covers zippers never designed to be locked, which on cheap daypacks and duffels is most of them.
It is a key lock, so nothing to memorise, and two keys plus printed instructions ship in the box, which addresses the missing-instructions problem that reviewers of other brands complain about. It also accepts the standard TSA key better than many competing locks.
When this is the right lock
This suits a traveller who moves through crowded places on public transport and does not want the pack to read as a target. It is also the right pick for zippers with tiny holes or no lock loop at all, because the detachable stem adapts.
Choose it if you want key convenience without the bulk of a conventional padlock.
When to skip it
Skip it if you are counting grams. At 49 g each it is among the heavier locks here, and across a multi-lock setup that adds up quickly against a onebag weight allowance.
Skip it if very small holes are your problem anyway. The ball-shaped cable end is slightly wider than the stated diameter, so the tightest holes may still refuse it.
8. Forge OX Dimple Key Lock 2-Pack — Best Lightweight Key Lock
Forge OX 1” Wide 1.8” Tall, TSA Approved Luggage Locks: Key Locks for Travel. Ultra Secure Dimple Key Travel Locks Alloy Body. for Luggage, Backpack, Small Toolbox and More. Black 2 Pack.
TSA006 dimple key
1.5 ounces per lock
1 inch square face,0.7 inch thick
Keyed alike pair
Pros
- Lightest lock in the roundup at about 1.5 ounces each
- Dimple key resists picking far better than cheap travel keys
- No combination to forget
- Alloy body with premium steel shackle
- One key opens both locks
Cons
- Only two locks per pack
- No inspection indicator
- You must keep track of the key
At roughly 1.5 ounces per lock, this is the lightest thing in the roundup, and it is a key lock, which means no dials, no code to forget, and no reset switch to fight in a hostel at midnight. Travellers who have locked themselves out with a forgotten code rate this format very highly.
The TSA006 dimple key is the substantive upgrade over cheap single-bitted travel keys. It resists picking and freezing considerably better, and the keys cannot be duplicated in a shop, which matters if you want the key not to be a skeleton for anyone who finds it.
The body is a compact 1 inch square face and 0.7 inch thick, with an alloy shell and a steel shackle. That is small enough for a laptop bag, a purse, or a small toolbox as well as a backpack, and the pair is keyed alike so one key covers both.
The limitation is honest and simple: two locks is a smaller pack than most multi-packs here, and there is no inspection indicator. If you want to know when a screener opened your bag, this will not tell you.
When this is the right lock
This is the pick for anyone optimising for every gram, and for travellers who simply do not want to remember a code. It works well for children and older travellers for the same reason.
It also suits small bags, where a 1 inch face is proportionate and a larger lock would look out of place.
When to skip it
Skip it if you travel with multiple bags and need to cover a lot at once. Two locks is not a group solution.
Skip it if losing small objects is a pattern for you. There is no recovery if the key goes missing.
9. Puroma 4-Digit TSA Cable Lock 2-Pack — Most Versatile
Puroma 2 Pack TSA Approved Luggage Locks 4 Digit Code Cable Lock Black
4-digit code with 10000 combinations
White numerals on black dials
Zinc alloy body with steel core
Flexible cable
Pros
- Four-digit code space at a low price
- White on black numbers readable in dim conditions
- Lightweight and compact for its security level
- Flexible cable handles small backpack zipper holes
- Weather and corrosion resistant
Cons
- Cable is less secure against cutting than a steel shackle
- Anyone with a TSA master key can open it
Most four-digit locks cost meaningfully more than three-digit ones. This one does not, and it holds a 4.6 rating from more than 3,500 reviews. If you want the code space without the price step, this is the pick.
The dials are the other reason it works at night. White numerals printed on black, rather than recessed into reflective metal, and the unlock-button design is easy to operate one-handed. That combination of legibility and one-handed operation is what you want on a dark platform with a bag in one hand.
The flexible cable is the part that earns its place in a backpack guide specifically. Rigid shackle locks need a real hole. This cable handles small fabric zipper pulls, daypack zips, and equipment cases, and the zinc alloy body with a steel core keeps the build from feeling cheap.
It is also weather, rust, and corrosion resistant, which reviewers with humid or coastal itineraries specifically call out as holding up over varied climates.
When this is the right lock
This suits a traveller who wants the stronger code space but travels light and does not want a rigid lock that will not fit softshell zips. It is a natural pairing with a small daypack on trains and ferries.
Choose it if you need two working locks and want the better code space on both.
When to skip it
Skip it if your bag goes into rough handling or you want resistance to cutting. A cable, however well built, loses to a steel shackle under a determined attack with cutters.
Skip it if you are locking to a fixed object. The cable is short and light by design.
10. Lewis N. Clark Triple Security Lock — Best for Anchoring
Lewis N Clark Triple Security Lock: TSA Luggage Locks for Suitcases, Carry On, Laptop Bag & More, Set Combination Lock to Create Secure Padlock for Travel, Vacation, Business, or Backpacking, 1 Pack
Two braided steel cables
3-dial resettable combination
Cast zinc alloy with ABS housing
6 x 2 x 6 in body
Pros
- Only lock here that anchors a bag to a fixed object
- Two cables make zip repair after tampering far harder
- Can chain two zipper pulls or a handle or a fixed point
- Keyless resettable combination
- Adds a second bag to your main pack
Cons
- Bulky 6 by 2 by 6 inch body
- Only 1000 possible codes
- Sold as a single lock so groups need several
This is the specialist pick, and the thing no other lock in this roundup does is anchor. It has two braided steel cables, which means it can lock your bag to a bed frame, a pipe, a locker frame, or a stair rail, not just close a zipper. If your real fear is a pack stowed out of sight on a night bus, this is the one built for it.
The second cable is also an anti-repair device. A thief who cuts a single cable can pull a zip and close it again behind them. Two cables crossing the same zipper pulls makes that repair much harder to disguise, which matters if a lock is ever forced.
You can also use it to attach a laptop bag, purse, or toiletry bag to your main luggage, which solves the small-bag problem that onebag travellers hit constantly. The keyless 3-dial reset removes any chance of a lost key.
The compromise is bulk. At 6 by 2 by 6 inches it is the largest body in this roundup, and it is sold as a single unit, so anyone anchoring several bags needs several locks. The 1,000-combination code is also on the weaker side.
When this is the right lock
Choose this if you regularly sleep in hostels, take night buses, or leave your pack in a shared room. Anchoring to a fixed object is a stronger deterrent than any lock on its own, and this is the only pick here that does it.
It is also good for tethering a smaller bag to a larger one on a long transit day.
When to skip it
Skip it if bag size and weight matter. The body is bulky enough to be visible and noticeable on a minimal setup.
Skip it if you want a discreet lock for city travel. This is the opposite of low-profile.
Cable vs Shackle vs Key: Which Lock Type for Which Backpack?
There are four lock families in this roundup, and the right one depends on your bag, not on your threat level. Here is how they actually differ.
Cable locks are the backpack default. A flexible steel cable threads through two zipper pulls, a fabric tab, or a small lock hole that a rigid lock would skip straight past. They are the most adaptable type by a wide margin and the lightest. Their weakness is obvious and worth stating plainly: a pair of wire cutters defeats a thin braided cable in seconds. They are a speed bump, not a barrier.
Rigid body and shackle locks resist cutting far better and suit hard cases, laptop bags, and lockers with a real hasp. They need a real hole, which softshell backpack zips often do not have. They are also heavier, which bites against strict carry-on weight limits.
Key locks remove the code from the equation entirely. Nothing to memorise, nothing to forget, and keyed-alike packs mean one key covers a whole group. The cost is recovery: lose the key abroad and the lock is finished. A dimple key system resists picking and freezing better than the cheap single-bitted travel keys sold next to it.
Multi-cable anchor locks are for the case where the bag leaves your sight. One lock in this roundup falls into this group, and it is the right answer for hostel dorms and night buses because it can attach to fixed hardware rather than just close a zip.
So is a visible lock a deterrent or an advertisement? It depends entirely on how it looks. A small, dark, low-profile lock on a softshell pack reads as an inconvenience and gets ignored. A bright, heavy padlock on a hiking pack reads as a challenge and, for a very small number of people, an invitation. The TravelMore in position seven is the deliberate answer for anyone who has decided that quiet beats visible.
For everyday commuting on public transport, which is the scenario that comes up most in the top forum thread on this topic, we would use a discreet key or cable lock on the main compartment. Nobody is trying to break in during a commute. They are trying to unthread a zipper while you are looking at a map, and a lock sitting flat on the panel stops that without drawing attention.
If your bag doubles as your work bag, sizing matters even more because you open and close it constantly. Our best laptop backpacks for business travel guide covers the compartment layouts that work best with a lockable main zip.
How to Choose a Travel Lock for Backpacks
Fit comes first, and it comes before any feature on any spec sheet. If the lock does not thread through your zipper pulls, nothing else matters. Measure as described above, and if you are still unsure, buy the two lightest locks on this list first and live with them for a month.
Next is where the bag actually spends its time. A bag that never leaves your side on a day trip does not need much. A bag that spends hours in a hostel dorm, an unattended bus bay, or a checked hold needs a real anchor point, and possibly a second lock. A bag you check should have a TSA-accepted lock for the reason covered in the next section.
Code space is the third decision. Three digits gives 1,000 combinations, which is plenty to stop someone guessing at random and inadequate to stop someone who genuinely wants in. Four digits gives 10,000, which is a tenfold improvement. The gap matters more for a bag left in a shared room than for one on your lap, and it costs you weight and grams of code space on a smaller body.
Weight is the fourth, and it is the one people forget until the gate. Nearly every airline weighs a carry-on, and the difference between a 49 g lock and a 2.1 ounce one is real. Four heavy rigid locks can add around 310 grams, which is enough to change a bag from comfortably under a limit to over it.
Keyed alike matters if you travel with anyone. One key across four locks beats four combinations remembered badly, and it is the reason the Master Lock 4683Q exists. If you travel solo, a two-pack still makes sense, because the second lock goes on a hostel locker or a daypack rather than sitting unused.
Finally, decide what you are actually protecting, and be honest about it. A lock secures a compartment. It does not protect a passport left in a side pocket or a laptop in an open main sleeve. Keep your passport, medication, and electronics on your body, in a money belt or a hidden pocket, and use the lock for the compartment that holds everything else. That single habit does more than any lock on this list.
When a bag is a main bag rather than an accessory, the choice starts with the bag itself. The best Nomatic travel backpacks and the convertible models we tested all differ in zipper layout, and that difference decides your lock more than any brand does.
TSA-Approved Locks: What to Know Before You Fly
Will TSA break TSA-approved locks? No. A TSA-approved lock carries the Travel Sentry red diamond, and screeners are required to open and relock it rather than cut it. A lock without that mark can and will be cut, along with the bag it is attached to, so if you check a bag, a TSA-accepted lock is close to mandatory.
Two different standards are in circulation. TSA007 is the older lock standard, still widespread and still accepted. TSA008 is the newer one, and a modern TSA master key is designed to open a TSA008 lock and cannot open a TSA007 lock, which means a newer-standard lock is the harder one to open without your code. Where you have a choice, newer is the better standard.
Here is the nuance most people get wrong: a TSA-approved lock is not approved for a security upgrade. It is approved for convenience. A screener, and anyone who obtains a master key, can open it by design. That is why TSA approval should never be the reason you choose a lock for a hostel locker.
And if you only ever carry on, a lock is optional. Nothing gets cut on a carry-on at the screening gate in normal operation. It becomes valuable the moment the bag is checked, handed off, or left with a hostel locker, so if you never do any of those, the honest answer is that you do not need one.
Frequently Asked Questions
What is the best security lock for backpacks?
The best security lock for backpacks is the SURE LOCK 3-Digit Cable Lock 2-Pack for most people, because its flexible cable threads through nearly any zipper pull and its open-alert button tells you if the bag was inspected. For stronger code space choose the Forge 4-Digit Combination Lock, which offers 10,000 codes instead of 1,000. For anchoring a bag to a fixed object, the Lewis N. Clark Triple Security Lock is the specialist option.
What are the best locks for travel bags?
The three best locks for travel bags in our testing are the SURE LOCK 3-Digit Cable Lock 2-Pack for softshell backpacks, the Forge 4-Digit Combination Lock for stronger code space and hard cases, and the BV 3-Digit Cable Lock 2-Pack for its compact weight and a body that spans two zipper pulls at once. Softshell bags need flexible cables because rigid shackles will not thread through fabric zipper pulls. Our separate guide covers hardshell rolling cases.
How do you lock your backpack when travelling?
Lock a backpack in four steps. First, pull the zipper sliders together on a dual-slider zip so both pulls sit at one point. Second, unlock the lock body and feed the cable or shackle through both pull tabs, or through a reinforced lock hole if the pack has one. Third, pull the cable tight so the sliders cannot be pushed back apart. Fourth, test it by unlocking and relocking twice before you rely on it. Add a second lock or a fixed-object anchor in hostels and on night buses.
Will TSA break TSA-approved locks?
No. TSA-approved locks carry the Travel Sentry red diamond, and screeners open and relock them instead of cutting. Locks without the mark can be cut, along with the bag. Note that a TSA-approved lock is approved for convenience, not for security: a screener or anyone with a TSA master key can open it by design, so TSA approval alone is not a reason to choose a lock for a hostel locker.
What is the best backpack lock for travel?
For a softshell backpack the best travel lock is a flexible cable combination lock, because a rigid shackle will not pass through fabric zipper pulls. Our top pick is the SURE LOCK 3-Digit Cable Lock 2-Pack, which is 70 g, has readable dials, and includes an open-alert indicator. If your bag has a side-opening compartment or a real reinforced lock hole, a rigid body like the Forge 4-Digit lock is the more secure option.
Is a visible lock a deterrent or does it advertise you have valuables?
It depends on how it looks. A small, dark, low-profile lock on a softshell pack reads as an inconvenience and gets ignored, which is why discreet bodies exist for city travel. A bright, heavy padlock can read as a challenge. Either way, a lock stops the opportunistic zip-and-grab theft that makes up almost all real incidents. It does not stop a determined thief with cutters.
Should I get a combination lock or a key lock for a backpack?
A combination lock suits solo travellers because there is no key to lose and no code to forget, provided you note your code somewhere. A key lock suits families and groups, where a keyed-alike pack means one key opens every lock. A dimple key system resists picking and freezing better than cheap single-bitted travel keys. Choose a key lock only if you are confident you will not lose it, because a lost key abroad has no recovery path.
Do I need a lock if I only carry on and never check a bag?
Not strictly. Nothing is cut from a carry-on at the screening gate in normal operation, so a lock on a bag that stays with you adds little. It becomes valuable the moment the bag is checked, stored in an open dorm room, put in a bus luggage bay, or placed in a hostel locker. Many onebag travellers keep a second lock in their daypack purely for that locker use.
Final Verdict
The best travel locks for backpacks are simple to choose once you understand that fit beats features. For most people on a softshell pack, the SURE LOCK 3-Digit Cable Lock 2-Pack is the backpack travel lock to buy: a cable that fits almost any pull, dials you can read in the dark, an indicator that tells you the bag was opened, and a second lock for a hostel room. At 4.7 stars across more than 16,000 reviews, it pairs a top-tier rating with a very large review base, which is the combination we weight most heavily here.
If code space is what worries you, the Forge 4-Digit Combination Lock is the upgrade at 10,000 combinations, accepting the extra weight. If the bag leaves your sight, the Lewis N. Clark Triple Security Lock is the only pick here that anchors to a fixed object. And if you want the lowest weight and the cleanest value, the BV 2-Pack at 2.1 ounces per lock is hard to argue with.
Whichever you pick, set the combination before you leave, test it ten times, and keep your passport, medication, and electronics on your body rather than in the pack. That habit is worth more than any lock on this list.