Perché serve salvare l'immagine in PNG e non in JPG?

Il messaggio viene nascosto modificando leggermente i bit meno significativi dei pixel (tecnica LSB). Il PNG è senza perdita e preserva questi bit esattamente; il JPG usa una compressione con perdita che altera i pixel e distruggerebbe il messaggio nascosto.

La steganografia LSB è sicura come una cifratura?

No, di base nasconde solo la presenza del messaggio da un'osservazione visiva, ma chi analizza i bit dell'immagine con strumenti dedicati può individuarlo. L'opzione di cifratura XOR aggiunge un ulteriore livello, ma non equivale a una cifratura robusta come AES.

L'immagine con il messaggio nascosto viene caricata su un server?

No, sia la codifica sia la decodifica del messaggio avvengono interamente nel browser: l'immagine non viene mai inviata altrove.

Online Steganography — Hide Messages in Images with LSB

When to use a steganography tool

This tool hides a text message in a PNG image's pixels using the LSB (Least Significant Bit) technique, with an optional additional XOR encryption layer, and extracts hidden messages from images that contain them.

When to use it

You want to hide a text message inside an image so it's not visible to casual observation.
You're studying or experimenting with steganography techniques for educational or technical purposes.

When NOT to use it

You need real security against dedicated technical analysis: LSB steganography hides a message from view, but doesn't protect it from someone actively analyzing the image's bits with dedicated tools.
You need to compress the image after hiding the message (e.g. convert it to JPG): lossy compression destroys the data hidden in the least significant bits.

Alternatives

Standard text encryption (AES) when the goal is content security, not hiding its existence.
More advanced steganography tools (with redundancy and error correction) for uses that require resistance to image manipulation.

Common mistakes

Saving or sharing the image with the hidden message in a compressed format (JPG) instead of PNG: the message hidden in the bits would be destroyed.
Thinking steganography replaces encryption: it hides the existence of the message, but if someone knows where and how to look, they can extract it, especially without the XOR encryption option enabled.
Using images too small for long messages: an image's capacity to hide text depends on the number of available pixels.

Frequently asked questions about image steganography

The message is hidden by slightly modifying the pixels' least significant bits (LSB technique). PNG is lossless and preserves these bits exactly; JPG uses lossy compression that alters the pixels and would destroy the hidden message.

No, by default it only hides the message's presence from visual observation, but someone analyzing the image's bits with dedicated tools can detect it. The XOR encryption option adds an extra layer, but it's not equivalent to robust encryption like AES.

No, both encoding and decoding of the message happen entirely in your browser: the image is never sent anywhere.

🕵️ Steganografia LSB

What is LSB steganography