Image Steganography Extractor
Extract hidden messages from steganographic image files. Auto-detect mode, bit plane analysis.
Drop image file or click to browse
PNG, BMP, WebP, TIFF, JPEG — max 50 MB (10 MB on mobile)
100% Client-Side Processing
Your image is decoded using the Canvas API entirely in your browser. Nothing is uploaded. Output is always lossless PNG.
How to Extract Hidden Data from an Image (5 steps)
- Upload the image that may contain hidden data.
- Select Quick mode for auto-detection, or choose a specific algorithm.
- Optionally enter a password if the data was encrypted.
- Click Decode — the tool extracts and interprets the hidden payload.
- Download the extracted file or copy the decoded text.
Image Steganography Methods — Detection Guide
| Method | Speed | Capacity | Use Case |
|---|---|---|---|
| Basic LSB 1-bit | ⚡ Fast | 📦 Medium | Short messages, maximum quality |
| Adaptive LSB | ⚡ Fast | 📦 High | Best balance — recommended default |
| Custom LSB (1–8 bit) | ⚡ Fast | 📦 Variable | CTF challenges requiring specific bit depth |
| DCT Domain | 🐢 Slow | 📦 Low | Images re-saved on social platforms |
| Spread Spectrum | ⚡ Fast | 📦 Very Low | Maximum stealth, small payloads |
Frequently Asked Questions
I don't know which algorithm was used — what should I do?
Use Auto-Detect mode. It tries all supported algorithms (LSB 1-bit, 2-bit, 3-bit, Adaptive LSB, DCT) and shows a confidence rating for each result. Select the one that looks like readable text or a recognizable file.
The output looks like garbage — is there hidden data?
Check the entropy score. High entropy (>7.2) suggests encrypted data — try entering a password. Low entropy with printable characters suggests plaintext. Very high entropy with no structure suggests the algorithm or bit depth doesn't match.
What is bit plane visualization?
Each pixel has 8 bits per channel. Visualizing each bit plane as a black/white image reveals patterns. LSB steganography appears as a noisy pattern in the lowest bit planes. This is a standard first step in manual steganalysis.
Can I extract data from a JPEG image?
JPEG compression destroys LSB data. If the image was encoded with DCT mode, try the DCT algorithm. Otherwise, JPEG images may have irretrievably corrupted hidden data. Enable RS Recovery if the encoder used Reed-Solomon error correction.
What are the R/G/B channel options for?
Some steganography tools hide data in only one channel (e.g., just the red channel). If auto-detect doesn't find anything, try each channel individually.
What does the String Extractor show?
Even when decoding doesn't fully succeed, printable ASCII strings (≥4 chars) are extracted from the raw bytes. CTF flags (FLAG{…}, HTB{…}, picoCTF{…}) are automatically highlighted.