Guide

How to hide a message

1. Choose Encode.
2. Drop in a carrier image. Photos and detailed images work best.
3. Enter the message you want to hide.
4. Add a password if you want the message encrypted before it is embedded. Without a password, the message is hidden but not encrypted.
5. Choose an output size. Original preserves the carrier image dimensions, Balanced keeps the image natural while reducing size, and Tiny makes a smaller file with more visible risk on simple images.
6. Download the generated PNG.

Keep the downloaded PNG intact. Many social networks, messengers, and image hosts resize or recompress images, which changes the pixel values and can destroy the hidden message.

How to reveal a message

1. Choose Decode.
2. Drop in the PNG created by Hide In Pixels.
3. Enter the same password used during encoding, if one was used.
4. Reveal and copy the message.

If decoding fails, the usual causes are a wrong password, a damaged or recompressed image, or an image that was never encoded by this tool.

The math behind it

Digital images store each pixel as color channels. In this tool, the useful channels are red, green, and blue. Each channel is a number from 0 to 255, which means it can be represented with 8 bits.

Hide In Pixels uses least significant bit steganography. Instead of changing the large bits that strongly affect color, it changes the final one or two bits in each red, green, and blue value. Changing a value from 146 to 147 is usually invisible, but that one-bit difference can carry data.

The approximate capacity is:

capacity bits = (width * height - 1) * 3 * bitsPerChannel

One pixel is reserved for format information. The 3 comes from the red, green, and blue channels. bitsPerChannel is usually 1, or 2 for the Tiny setting.

The message is converted to bytes, prefixed with a small length header, and then written bit by bit into the carrier image. When a password is provided, the message is first encrypted with AES and the encrypted text is what gets embedded.

Why this is useful

Steganography hides the fact that a message exists. Encryption protects the contents of a message, but encrypted text still looks like encrypted text. A steganographic image looks like an ordinary image while carrying extra data.

That makes the tool useful for:

• Adding private notes to images you keep for yourself
• Sending low-risk hidden messages where the image file can stay unchanged
• Understanding how image steganography works in a hands-on way
• Embedding small metadata or reminders without using visible captions

This is not a replacement for a dedicated secure messenger. Use it for practical privacy, experimentation, and low-stakes hidden notes, not for situations where discovery would create serious risk.

Good carrier images

Detailed photos usually hide changes better than flat illustrations, screenshots, logos, or images with large areas of solid color. Bigger images can carry more data. Short messages are more robust and less likely to require visible tradeoffs.