Image Steganography
Hide an encrypted text message inside an image, or reveal one.
A Message Hidden In Plain Sight
Type a message and it is written into the least significant bit of each colour value in an image — a change of at most one step in 255 that no eye can see. The image looks the same; the message is inside it. Load that image back here to reveal the message.
Add a password and the message is first encrypted with AES-256-GCM, with the key derived by PBKDF2 over 250,000 rounds, so even someone who knows where to look reads only noise. The output is always a lossless PNG — the only kind of file that carries hidden bits intact.
Key features
- LSB steganography — invisible changes to the pixels.
- Optional AES-256-GCM encryption with a password.
- Capacity meter — how much text the image can hold.
- Reveal mode reads and decrypts hidden messages.
- Offline and private — nothing leaves your device.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Image Steganography
- Drop in a cover image
Larger images hold longer messages. - Write the message
Optionally add a password to encrypt it. - Download the PNG
It looks identical to the original. - Reveal later
Switch to Reveal, add the PNG and the password.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Security |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Why did my hidden message disappear?
The image was probably recompressed. WhatsApp, Facebook, Instagram and most messengers convert images to JPEG, which destroys the least significant bits. Send the PNG as a file or document, or share it by email or cloud storage.
Why is the output PNG bigger than my JPEG?
PNG is lossless, and it has to be — lossy formats would wipe the hidden bits. A photo stored losslessly is usually several times larger than the same photo as a JPEG.
Can someone detect that a message is hidden?
Statistical steganalysis can sometimes detect LSB embedding, especially of long messages. With a password, a detected message is still unreadable without it. For real secrecy, rely on the encryption, not on the hiding.
How much text can an image hold?
Three bits per opaque pixel: a 1920 × 1080 image holds about 777 KB. The capacity meter shows the exact figure for your image.
Does it work with transparent images?
Yes. Only fully opaque pixels carry data, so transparent areas stay exactly as they were.