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Steganography

Hide a secret message or small file inside an image, with an optional password, and reveal it later.

Free, no uploads, no sign-up. Runs 100% in your browser.

How Steganography works

Everything happens in your browser with the Web Crypto API and plain JavaScript. Nothing is uploaded, so the files and passwords never leave this device. The message is written into the lowest bit of the red, green and blue values (LSB), which changes each colour by at most one step. A password adds AES-256-GCM encryption first.

Input: PNG, JPG, WEBP. Output: PNG.

How to use Steganography

1. Drop a cover image.
2. Type the message or drop a small file.
3. Add a password if you like, then press Hide it.
4. Share the PNG. To read it, open the Reveal tab and drop the image.

Tips

• Send the PNG as a file. Social sites and chat apps re-compress images and destroy the message.

Steganography FAQ

Are my files uploaded?

No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.

Is it free? Are there limits or watermarks?

Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.

Does it work offline?

Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

Related tools

• Encrypt / Decrypt Text & Files: Password-protect text or any file with AES-256-GCM, ChaCha20-Poly1305 or OpenSSL-compatible AES.
• Locked HTML File: Lock a file or note inside a single HTML page that opens in any browser with your password, no app needed.
• Password ZIP: Make an AES-256 password-protected ZIP that opens anywhere, or unlock one you have the password for.
• Metadata Scrubber: Remove hidden data from photos, PDFs, Office files and MP3s in one batch: GPS, camera, author, company and more.