How to hide text in an image
Hide a secret message inside a picture in your browser. Nothing is uploaded, the image looks identical, and only someone with the file can read it back.
· · 3 min read
Step 1: Open the tool in hide mode
Go to Hide Text in Images. It opens in Hide mode by default. The other tab is Reveal, which does the opposite.
Everything runs in your browser. Your picture and your message are never uploaded anywhere.
Step 2: Add a picture
Drag in a photo or click to pick one. Most common image formats work as the starting picture.
Bigger pictures hold more text. The tool shows you the capacity for whatever you upload, measured in characters, and warns you if your message is too long for the image you chose.
Why capacity varies: the message is stored across the image's pixels, three bits per pixel. More pixels, more room. A phone photo holds a novel. A small icon holds a sentence.
Step 3: Type your message
Write whatever you want to hide. The character counter fills up as you type, and turns into a warning if you go past what the picture can hold.
If you run out of room, either shorten the message or start from a larger picture.
Step 4: Download the PNG
Click to hide the message, then download the result.
The download must stay a PNG. This is the one rule that matters, and the reason is worth understanding:
- PNG is lossless. Every pixel is preserved exactly, so the hidden bits survive.
- JPG is lossy. It rebuilds the image approximately to save space, which quietly destroys the hidden message.
If you convert the file to JPG, screenshot it, or send it through something that re-compresses images, the message is gone. Not corrupted. Gone.
Step 5: Send it in one piece
Anything that re-encodes the picture will strip the message out. In practice that means:
Usually safe: sending the PNG as a file attachment, an email attachment, a direct file transfer, a download link.
Usually destroys it: posting to most social networks, most chat apps that compress images, screenshotting it, saving it as JPG.
If you are not sure whether a service re-compresses, send it to yourself first and check it in Reveal mode.
What this is not
Being honest about the limits:
- This is not encryption. There is no password. Anyone who suspects a message is there and runs the picture through the same kind of tool can read it.
- It hides that a message exists, which is a different thing from making it unreadable. If you need real secrecy, encrypt the text first and hide the encrypted version.
- It does not survive editing. Crop it, filter it, resize it, or re-save it, and the message goes with it.