Security

Image Steganography

Hide a short text message inside a PNG’s pixel data, or reveal one that’s already hidden.

Runs entirely in your browser, nothing is uploaded

Message to hide

Cover image (use PNG, since JPEG’s compression destroys hidden bits)

Drop a file here, or click to browse

PNG image · up to 20.0 MB

Encodes each bit in the least-significant bit of a pixel’s red/green/blue channel. Downloading, then re-uploading, or any lossy re-encoding (like converting to JPEG), destroys the hidden data, since it relies on exact pixel values.

How it works

1
You choose an image and a message
Both are handled in the page through a canvas. Neither is uploaded.
2
The message goes into the pixels
Each character is written into the least significant bits of the image data, along with a short header so the reader knows how much to read back.
3
You save a PNG
PNG is used because it is lossless. Re-saving the result as JPEG would discard the hidden bits.

Practical guidance

This hides a message, it does not encrypt one. Anyone who suspects the technique can recover it, so encrypt the text first if it actually matters.
Capacity depends on image size. A short message needs a surprisingly large image.
Anything that recompresses the file, including most messaging apps and social networks, will destroy the hidden data.

Image Steganography

How it works

You choose an image and a message

The message goes into the pixels

You save a PNG

Practical guidance

People usually pair this with

Hidden Character Detector

Image Forensics

Suspicious File Extension Analyzer

Image Steganography

How it works

You choose an image and a message

The message goes into the pixels

You save a PNG

Practical guidance

People usually pair this with

Hidden Character Detector

Image Forensics

Suspicious File Extension Analyzer