INSTRUCTIONS

What this tool does

inplain.site lets you hide an encrypted message (and optionally a file) inside a PNG image.

Only someone with:

• the stego image, and
• the correct password

can recover the hidden content.

Everything happens in your browser. No images or messages are sent to a server.

1. Choose what you want to do

You can use the tabs at the top:

• ENCODE - hide a message (and optional file) inside a PNG.
• DECODE - try to recover a hidden message/file from a PNG.

Start on ENCODE if you're creating a secret image.
Use DECODE if someone has sent you an image and a password.

2. Hiding a message (ENCODE)

1. Select a cover image
   • Drag & drop a PNG, JPEG, non-animated GIF, or WebP into the "Cover image" panel, or click Browse files.
   • The image is flattened and converted to PNG internally before embedding. The output download is always a PNG.
2. (Optional) Write your message
   • Type your secret text into the Message box on the right.
   • You’ll see the character count and how much capacity the image has.
3. (Optional) Attach a file
   • Use the file section to attach a single file (any type, capacity permitting).
   • The file will be hidden alongside your message, or on its own if you leave the message box empty.
4. Choose a strong password
   • Enter a password in the Password section and confirm it.
   • The same password will be needed to decode later.
   • If you forget it, there is no recovery.
5. Check capacity
   • The capacity bar shows how much space your message/file uses inside the image.
   • If the payload is too large for this image and settings, the app will tell you.
6. Encode
   • Click ENCODE.
   • The Process log will show each step (encryption, packing, hiding in pixels).
   • When it finishes, you’ll be given a downloadable PNG.
7. Share the stego image
   • Send the resulting PNG to your recipient using any normal channel (email, messaging app, file share, etc.).
   • Separately, share the password with them in a safe way.

3. Revealing a hidden message/file (DECODE)

1. Go to the DECODE tab.
2. Select the stego image
   • Drag & drop the PNG you received into the ’'?oStego image’'?? panel, or click Browse files.
3. Enter the password
4. Click DECODE.
5. Watch the Process log for progress.
6. If the password is correct and the image contains valid data:
   • Any hidden message will appear in the Decoded message panel.
   • Any hidden file will show as a downloadable entry (with its name and size).
7. If the password is wrong or the image has been modified:
   • You will see a long block of random-looking text (’'?ojunk’'??) instead of a neat error.
   • This is intentional and makes it harder to learn anything from failed attempts.

4. Tips and limitations

• Mobile supported - mobile and tablet browsers are supported, but performance depends on device and image size.
• PNG output only - uploads can be PNG, JPEG, non-animated GIF, or WebP; they are flattened and converted to PNG before encoding.
• Keep a copy of the original stego image – re-saving or editing the image in other tools can destroy the hidden data.
• Passwords are everything – there is no backdoor or reset; if you lose the password, the content is effectively gone.
• Be cautious where you upload – some sites re-compress or resize images, which will break the hidden data.