Locking or password protection: which one do you need?
Locking is permanent and applies to everyone, including you. A password blocks others while leaving you in control, provided you keep the key. Most people who lock a tag would have been better served by a password, and most do not realise the option exists.
The difference in one line
Locking says nobody may write, ever, including you. A password says only someone holding this key may write.
Everything else follows from that, and it is remarkable how often the distinction is missed, because tools present the two options side by side with no explanation of how differently they behave.
Side by side
| Property | Locking | Password |
|---|---|---|
| Reversible | Never | Yes, with the key |
| You can still write | No | Yes |
| Available on all tags | Effectively yes | Only on chips that support it |
| Survives formatting | Nothing survives, nothing can be formatted | Yes, it is chip configuration |
| Risk if you lose control | None, it is already final | Tag becomes unwritable |
| Protects against reading | No | On some chips, optionally |
Choosing between them
Choose a password when you might want to change the content and want to stop others doing so. That describes most deployments honestly examined.
Choose locking when the content genuinely will never change, and when losing a key would be a worse operational problem than losing the ability to edit. A large distributed run of tags carrying a stable redirect is the clear case.
Choose neither for personal tags, tags in controlled spaces, and anything you are still iterating on.
The uncomfortable observation is that people reach for locking because tools put it next to the write button and passwords are buried in a configuration screen. That is an interface accident, not a recommendation.
Using both
They combine, and the combination is occasionally right.
Set a password during a deployment so tags remain correctable by your team, then lock them at the end of the campaign when the content is final. You keep flexibility while it matters and gain permanence once it does not.
What does not work is locking first and hoping the password saves you. Once locked, the password area may itself be frozen, and in any case there is nothing left to protect.
Frequently asked questions
Do all tags support passwords?
No. Simpler chips offer locking and nothing else, while more capable families add password protection. This is decided by the chip reference, so it belongs in the purchase decision.
Is a password as strong as locking?
Against a casual passer by with a phone, yes, since they do not have the key. Against a determined attacker the comparison is different, and neither mechanism was designed for that fight.
Can I change a password later?
Yes, with the current one. That is precisely what makes it a different tool from locking, and it is also why losing the key matters.
Which should I use for a public poster?
A password if the chip supports one and you may want to update the content. Locking if the content is a stable redirect and you want the simplest possible permanence.