File Locker

Lock any file with a password: tax papers, IDs, contracts, photos. The locked copy opens anywhere with just the password, not only on this website. Email it, put it on a USB stick or in the cloud, and only someone with the password can read it.

🔒 Files never leave your device

What “files never leave your device” means for this tool

When you open this page, your browser downloads the locker itself, the same way any web page loads. From then on, locking and unlocking happen inside your browser, on your own device. Your files and your password are never sent to this website's server or to anyone else. Want proof? Turn off Wi-Fi after the page loads; it keeps working.

Nothing is kept. There is no copy of your file or password anywhere but the locked file you download. That is also why a forgotten password cannot be reset: nobody, including this site, can open the file without it.

What the server does see: like any website, the server that delivers this page sees basic connection details such as your IP address and which page was requested. Never your files or password.

Visit counting: this site counts visits with privacy-friendly analytics. No cookies, no ads, no tracking across other sites, and your IP address is not stored. It records which page you opened, your country, your device type, how long you stayed and when you lock or download a file, never the file, its name or the password.

1. Choose files

Drop files here
or click to choose. Any kind of file, one or many.

2. Pick how it opens

Self-unlocking file (.html) Double-click it and it opens in any web browser (Chrome, Edge, Firefox, Safari), even with no internet. Type the password and save the file. Nothing to install. The strongest protection here. Password zip (.zip, AES-256) Opens in free unzip apps: 7-Zip or WinRAR on Windows, Keka or The Unarchiver on Mac, most Android file managers. Windows' and Mac's built-in unzip can't open it. Use a long password: the zip format guesses faster.

3. Set a password

Show

A forgotten password cannot be recovered. Not by you, not by this site, not by anyone. Save it in a password manager or write it down before you lock.

I have saved the password somewhere safe.

How the lock works

Your password becomes a key. Your browser runs it through PBKDF2, a deliberately slow scrambler (600,000 rounds), so each password guess takes real time. Guessing a strong password would take longer than anyone has.
The file is encrypted with AES-256, the standard used by banks, governments and password managers. A tamper check is built in, so a changed or damaged file is refused, never opened as garbage.
The real file name is locked inside too. The locked copy is named after it (like photo-locked.html) so you can find it; rename it if the name itself is private.
The unlock code travels with the file. The self-unlocking .html carries its own small unlock page and a description of the format, so it doesn't depend on this website still existing.

	Self-unlocking .html	Password zip
Opens with	Any web browser, offline	7-Zip, WinRAR, Keka, The Unarchiver
Key strength	PBKDF2-SHA256, 600,000 rounds	PBKDF2-SHA1, 1,000 rounds (zip standard)
File names hidden	Yes, inside (rename the outer file if needed)	No, names are visible
Size limit here	300 MB	1.5 GB

How to use the File Locker

Drop in the files you want to lock.
Pick a self-unlocking file (opens in any browser) or a password zip (opens in 7-Zip, WinRAR, Keka).
Set a strong password and save it somewhere safe.
Press Lock & download, then send or store the locked file.

Questions

Does the person I send it to need this website?

No. A self-unlocking file opens in any web browser with just the password, even offline. A password zip opens in 7-Zip, WinRAR, Keka or The Unarchiver.

What if I forget the password?

The file cannot be opened by anyone, including this site. There is no reset. Save the password in a password manager before you lock.

How strong is the encryption?

AES-256, with the password strengthened by 600,000 rounds of PBKDF2 for self-unlocking files. With a long, random password it cannot be guessed in any realistic time.

Why can't Windows open the password zip?

Windows' built-in zip support only knows an old, weak kind of zip password. Strong AES zips need a free app such as 7-Zip. Choose the self-unlocking file if the other person won't install anything.

Why can't I lock a program as a self-unlocking file?

Programs, scripts and web pages can only be locked as a password zip, so self-unlocking files can't be used to slip harmful downloads past email filters.

Are my files uploaded?

No. Locking and unlocking happen on your device. The file and the password never leave your browser.

Still stuck, or want a tool that isn't here? Ask on the Nebula Discord.