Web Demo · Stego-Lab
Try Stego-Lab yourself: download one of the sample images and decode it in the app. All images were created with Stego-Lab.
Important: transfer the images unchanged
Hidden data lives in the individual pixels. Messengers such as WhatsApp or Signal, screenshots and image editing change these pixels – afterwards nothing can be found. On iPhone/iPad save the image to Files (or send it via AirDrop); on the Mac simply download it.
Four levels to try
Levels 1 to 3 use the same white tiger as carrier.
Level 1 · Text without password Free
A hidden text that is shown immediately – no Stego-Lab Pro needed.
Password: none · PNG, approx. 2 MB
Level 2 · Text with password Pro
Same steps, but the text is encrypted with AES-256-GCM. Stego-Lab detects this and asks for the password.
Password: StegoReview2026 · PNG, approx. 2 MB
Level 3 · Image with password Pro
The tiger hides a complete second photo, also encrypted. After decryption a black cat appears.
Password: StegoReview2026 · PNG, approx. 2 MB
Level 4 · AI image with labelling Free
An AI-generated cat, labelled as required by Art. 50 of the EU AI Act: a visible label in the picture, machine-readable metadata and an invisible disclosure in the pixels. Plus a hidden text.
Password: none · PNG, approx. 1.5 MB
How it works
- Download the image (see the note above).
- iPhone/iPad: open Stego-Lab, go to Decode, then “Aus Dateien” (from Files) or “Aus Fotos” (from Photos). Mac: go to Entdecken (Decode), “Bild öffnen…” or drag the image into the window.
- For levels 2 and 3 a password field appears: enter the password and tap or click Dekodieren (Decode).
Check the AI labelling (level 4)
The cat was generated with Google Nano Banana 2 (via Higgsfield) and labelled with Stego-Lab. Load the image in Decode (Mac: Entdecken): next to the hidden text the badge “KI-Kennzeichnung erkannt” (AI labelling detected) appears with all three sources. The EXIF area shows the written fields (IPTC Digital Source Type, XMP, EXIF image description).
Where is the message?
Stego-Lab only changes the last bit of a colour value (LSB, “least significant bit”). In the level 3 image, 251,625 of 1,638,400 pixels changed – each by at most 1 of 255 brightness steps. The naked eye cannot see it.
That is why steganography only works with lossless formats such as PNG or TIFF: JPEG compression rounds away exactly these last bits.
Large sample image
The previous sample image (18 MB) also contains hidden content.
⬇︎ Download large sample image (18 MB)
We deliberately do not offer in-browser decoding: this page loads no scripts and sends nothing to a server (no tracking, no cloud backend). The actual processing happens locally in the app – exactly as Stego-Lab's privacy promise intends.