Free Online Steganography Tools
StegoToolkit provides free online steganography tools for hiding, extracting, detecting, and analyzing hidden data in images, audio files, PDFs, text, SVG, and more. Use our steganography encoder, decoder, and analyzer directly in your browser — no software to install, no uploads, no account required.
Forensic analysis tools to detect and investigate steganographic content
StegSolve Online
AnalyzerFull StegSolve.jar in your browser. 28 bit planes, auto-scan, chi-square LSB detection, brute-force extractor, PNG chunk analysis, stereogram solver. No Java, no install.
Steganography Analyzer
AnalyzerDetect and analyze steganographic content in images. Chi-Square, RS Analysis, Sample Pairs, Primary Sets. Bit plane viewer. Forensic report. No upload.
Embed and decode secret data inside PNG, BMP, and WebP images
Hiders
Extractors
Text-in-Image Hider
HiderHide secret text messages inside images using adaptive LSB steganography. PSNR/SSIM quality report, chi-square vulnerability score, AES-256 encryption. Always outputs PNG.
Text-in-Image Extractor
ExtractorExtract hidden text from images. Auto-detects 11 LSB configurations. Bit plane visualizer, chi-square pre-scan, CTF flag detection. Browser alternative to zsteg and Stegsolve.
Image Steganography Hider
HiderHide secret messages or files inside PNG, BMP, or WebP images. AES-256 encrypted, 100% client-side.
Image Steganography Extractor
ExtractorExtract hidden messages from steganographic image files. Auto-detect mode, bit plane analysis.
LSB Embedder
HiderHide text or files in PNG/BMP images using Least Significant Bit steganography. Sequential or PRNG pixel order. Variable bit depth. AES-256. Real-time stealth score.
LSB Extractor
ExtractorExtract hidden LSB steganography from PNG/BMP images. Auto-detects LSBSTEG format. Ranked heuristic scan (10 CTF patterns). Bit plane viewer. Flag detector.
Image-in-Image Hider
HiderHide a secret photo invisibly inside any cover photo. Variable bit depth, AES-256 encryption, PSNR quality report, extraction preview. The only professional browser tool for image-in-image steganography.
Image-in-Image Extractor
ExtractorExtract hidden images from stego photos. Auto-detects 12 configurations (4 bit depths × 3 channels). Bit plane visualizer, pre-scan anomaly detection, AES-256 decryption, forensic report.
Image Watermark Embedder
HiderAdd visible copyright overlay and/or invisible DWT+DCT frequency watermark to images. Robustness survival test included. No upload — 100% client-side.
Conceal messages within WAV and MP3 audio files
Hiders
Extractors
Audio Steganography Hider
HiderHide text or files inside WAV or MP3 audio with AES-256 encryption, Reed-Solomon ECC, capacity meter, and SNR quality report. 100% client-side.
Audio Steganography Extractor
ExtractorExtract hidden text or files from WAV or MP3 audio. Auto-detect all algorithms, AES-256 decryption, CTF flag highlighting. 100% client-side.
MP3 Steganography Embedder
HiderHide secret text in MP3 files using ID3v2 tag, frame padding, or part2_3_length parity (MP3Stego compatible). AES-256. No upload. 100% client-side.
MP3 Steganography Extractor
ExtractorExtract hidden messages from MP3 files. Auto-detects ID3v2, frame padding, and parity methods. MP3Stego compatible. CTF flag detection. No upload.
Hide payloads inside MP4, AVI, MKV, and WebM video files
Hiders
Extractors
Hide and extract secret payloads inside PDF documents
Hiders
Extractors
PDF Steganography Hider
HiderHide secret text or files inside PDF documents using advanced steganography algorithms. AES-256 encrypted, 100% client-side.
PDF Steganography Extractor
ExtractorExtract hidden messages and files from steganographic PDF documents. Auto-detects encoding method.
Encode secret data inside SVG vector graphics using XML-native methods
Hiders
Extractors
Steganography for plain text, zero-width Unicode, and whitespace
Hiders
Extractors
Invisible Text Hider
HiderHide secret messages inside any visible text using invisible zero-width Unicode characters. AES-256 encrypted. Platform-aware (Gmail, Discord, Twitter). 100% client-side.
Invisible Text Extractor
ExtractorDetect and extract hidden messages from text containing zero-width Unicode characters. Auto-detect encoding. AES decryption. CTF flag detection. 100% client-side.
Text Steganography Hider
HiderHide secret messages or watermarks in plain text using Unicode homoglyphs, trailing whitespace (SNOW-compatible), Unicode spaces, or inter-word spacing. AES-256-GCM encryption + Reed-Solomon error correction. 100% client-side.
Text Steganography Extractor
ExtractorAuto-detect and extract hidden messages from plain text using homoglyph, whitespace, and spacing methods. Instant anomaly detection. Watermark attribution for leak detection. SNOW-compatible. 100% client-side.
Create polyglot files with hidden payloads inside any carrier
Hiders
Extractors
File Hider
HiderHide any file inside another file (JPEG, PNG, MP3, PDF). Creates polyglot files that open normally but contain hidden payloads. AES-256 encrypted.
File Hider Extractor
ExtractorExtract hidden files from polyglot carriers. Browser-based binwalk alternative with auto-detect, AES decryption, and visual hex map.
Hide data inside DOCX, XLSX, PPTX, and ODT Office documents
Hiders
Extractors
Document Steganography Hider
HiderHide text or files inside DOCX, XLSX, PPTX, or ODT documents using OOXML Custom XML Parts or ZIP comments. AES-256 encryption. 100% client-side.
Document Steganography Extractor
ExtractorExtract hidden payloads from DOCX/XLSX/PPTX/ODT documents. Auto-detects Custom XML Parts and ZIP Comments. AES-256 decrypt + CTF flag detection.
Conceal messages in HTML using zero-width chars, comments, and whitespace
Hiders
Extractors
HTML Steganography Hider
HiderHide secret messages inside HTML files using zero-width characters, comments, whitespace, attribute order, case variation, and entity substitution. AES-256 encrypted. Zero visual change.
HTML Steganography Extractor
ExtractorFind hidden messages in HTML files. Detects zero-width characters, comment encoding, whitespace patterns, and more. Auto-detect mode, CTF flag detection, AES decryption.
Embed hidden data inside fully scannable QR codes
Hiders
Extractors
QR Code Steganography Hider
HiderHide secret messages inside fully scannable QR codes. Uses LSB pixel encoding, module color steganography, and PNG metadata embedding. The QR still scans normally while carrying a hidden payload.
QR Code Steganography Extractor
ExtractorExtract hidden payloads from steganographic QR codes. Auto-detects method across LSB, module color, and PNG metadata. Shows QR anomaly score and per-method results.
Miscellaneous steganography analysis and utility tools
What is Steganography?
Steganography is the practice of concealing a secret message inside an ordinary, non-secret file — so only the intended recipient knows the hidden data exists. Unlike cryptography, which makes data unreadable, steganography hides the very existence of the message. A steganographic image looks pixel-perfect to the human eye; the payload is invisible without the right extraction tool.
With free stego online tools, this is now possible from any browser without installing steganography software. Carrier formats include digital images (PNG, BMP, WebP), audio (WAV, MP3), video (MP4, MKV, WebM), PDF, SVG, Office documents (DOCX, XLSX, PPTX), HTML, and plain text.
How Steganography Works
Steganography hides information inside a carrier file using one of four techniques. The carrier looks completely normal to anyone without the matching extraction tool.
LSB Encoding
Replaces the least-significant bits of pixel or audio sample values with payload bits. Invisible at 1–2 bit depth and the most widely used technique.
Transform-Domain Embedding
Hides data in DCT (JPEG) or DWT frequency coefficients rather than raw values — survives compression and is harder to detect statistically.
Metadata Injection
Stores payloads in EXIF fields, ID3 tags, PDF object streams, or Office XML parts with zero modification to the visible content.
Unicode Manipulation
Encodes binary data as invisible zero-width characters (U+200B, U+FEFF) or homoglyphs inserted into plain text or HTML.
Types of Steganography
Image Steganography →
Hides data in pixel values using LSB, DCT, or spread-spectrum methods. The most common format for CTF challenges and covert communication.
Audio Steganography →
Embeds payloads in WAV or MP3 audio samples. Techniques include LSB encoding, phase coding, and ID3v2 tag injection.
PDF Steganography →
Conceals data inside PDF structure — whitespace, comments, object streams, and metadata — without affecting the visible document.
Text Steganography →
Uses zero-width Unicode characters, trailing whitespace, or homoglyph substitution to hide messages inside plain text.
Common Use Cases
CTF & security research — Capture-the-flag competitions regularly hide flags inside images, audio, and PDFs. Our steganography detection tools and StegSolve Online are purpose-built for forensic CTF workflows.
Digital watermarking — Embed invisible ownership marks into images or documents to trace leaks, prove copyright, or identify recipients of confidential files.
Covert communication — Pass sensitive information inside innocent-looking files without raising flags, useful in journalism and privacy research.
Steganography Detection Tools
Detecting hidden steganographic content — called steganalysis — requires statistical analysis of the carrier file. Our Steganography Analyzer runs four statistical tests (Chi-Square, RS Analysis, Sample Pairs, Primary Sets) and produces a fusion suspicion score and bit-plane visualizer — the same techniques used in professional steganalysis. The StegSolve Online tool adds 28 bit-plane views, QR auto-scan, and a 255-combo brute-force hidden message decoder — a full browser replacement for StegSolve.jar.
Popular Steganography Software Alternatives
All of these desktop tools are available as free online alternatives — no download required.
StegSolve Online →
Browser port of StegSolve.jar — 28 bit-plane filters, QR auto-scan, 255-combo brute-force hidden message decoder, and histogram view.
Image Steganography Online →
Hide and extract secret messages inside PNG, BMP, and WebP images using LSB encoding — no upload, no install, fully in-browser.
Steganalysis Detector Online →
Detect hidden steganographic content using Chi-Square, RS Analysis, Sample Pairs, and Primary Sets tests — with a fusion suspicion score and bit-plane visualizer.
Image Stego Extractor Online →
Extract hidden messages from PNG, BMP, and WebP images. Auto-detects algorithm and bit depth, with CTF flag highlighting and entropy analysis.
Image Watermark Embedder Online →
Embed invisible ownership watermarks into images using DWT+DCT frequency-domain encoding — survives compression and resizing.
Audio Steganography Online →
Hide secret messages or files inside WAV audio tracks using LSB encoding — no upload, no install, processed entirely in your browser.
Popular Steganography Methods
Least Significant Bit (LSB)
The most widely used technique. Replaces the 1–4 least-significant bits of pixel or audio sample values with payload data. Imperceptible at low bit depths and easy to implement.
Transform-Domain (DCT / DWT)
Embeds data in frequency coefficients (DCT for JPEG, DWT for images) rather than raw pixel values. More robust against compression, resizing, and statistical steganalysis.
Metadata Steganography
Hides payloads inside file metadata — EXIF tags in images, ID3 frames in MP3s, PDF object streams, or custom XML parts in Office documents. No pixel-level changes.
Unicode Steganography
Encodes binary data as invisible zero-width Unicode characters (U+200B, U+200C, U+FEFF) inserted into plain text or HTML. Completely undetectable by visual inspection.
Polyglot File Embedding
Appends a hidden file to the end of a valid carrier (JPEG, PNG, MP3, PDF). The carrier opens normally in its native app while the hidden file can be extracted by offset.
Office Document Steganography
Uses OOXML structure (DOCX, XLSX, PPTX are ZIP archives) to store hidden data in custom XML parts, ZIP comments, or relationship files without altering visible content.
Frequently Asked Questions
What is steganography?
Steganography is the practice of hiding secret information inside an ordinary, non-secret file — called a carrier — so that the existence of the hidden message is not apparent. Unlike encryption, which scrambles data to make it unreadable, steganography hides the fact that a message exists at all. Common carrier formats include images, audio files, PDFs, video, SVG graphics, and plain text.
What is a steganography decoder?
A steganography decoder (also called an extractor) reverses the embedding process to recover hidden data from a carrier file. You supply the carrier file, optionally provide a password if the payload was encrypted, and the decoder outputs the hidden message or file. StegoToolkit provides online steganography decoders for every major format — images, audio, PDF, video, SVG, text, and more — all running in your browser.
What is a steganography encoder?
A steganography encoder (also called a hider or embedder) takes a carrier file and a secret payload, and produces an output file that looks identical to the carrier but contains the hidden data. Most steganography encoders support optional AES-256 encryption so the payload is unreadable even if someone detects that steganography was used.
Is steganography legal?
Steganography itself is legal in most countries and has many legitimate uses: digital watermarking, covert communication in journalism, CTF security competitions, copyright protection, and privacy research. Using steganography for illegal purposes (fraud, distributing illegal content, etc.) is illegal regardless of the technique used. Always ensure you have permission before analyzing files you did not create.
What file types support steganography?
Almost any file format can carry steganographic data. The most common are lossless images (PNG, BMP, WebP), audio files (WAV, MP3), video (MP4, MKV, WebM, AVI), PDF documents, SVG vector graphics, Office documents (DOCX, XLSX, PPTX, ODT), HTML files, and plain text. Lossy formats like JPEG and MP3 require transform-domain techniques (DCT, frame-parity) to survive compression.
What steganography tools are available online?
StegoToolkit offers 29 free steganography tools online across 12 categories: image (PNG/BMP/WebP), audio (WAV/MP3), video (MP4/MKV/WebM), PDF, SVG, text, binary/file, Office documents, HTML, QR codes, and forensic analysis. Every tool runs as stego online — 100% in your browser with no software to install.
How do I use the steganography encoder to hide a secret message?
Open the matching steganography encoder for your file type (e.g. Image Steganography Hider for PNG/BMP, Audio Steganography Hider for WAV). Upload your carrier file, enter your secret message or upload a file to hide, choose an algorithm, optionally add AES-256 encryption, and download the output. The result is visually and audibly identical to the original.
Which tool should I use as an online steganography decoder?
Use the steganography decoder that matches your carrier format: Image Steganography Extractor for images, Audio Steganography Extractor for WAV, MP3 Steganography Extractor for MP3, PDF Steganography Extractor for PDFs, and so on. Every online steganography decoder includes an auto-detect mode that tries all known algorithms automatically — ideal when you don't know how the data was hidden.
Is there a free steganography software alternative that runs in the browser?
Yes — StegoToolkit is a complete browser-based alternative to desktop steganography software like OpenStego, SteghideGUI, and DeepSound. All 29 tools run client-side using WebAssembly and the Web Crypto API. No download, no install, and no files ever leave your device.
How do steganography detection tools work?
Steganography detection tools (steganalysis) look for statistical anomalies that embedding leaves behind. StegoToolkit's Steganography Analyzer runs Chi-Square, RS Analysis, Sample Pairs, and Primary Sets tests to produce a fusion suspicion score. StegSolve Online adds 28 bit-plane views and a brute-force hidden message decoder. Both tools work entirely in your browser.
Do these stego tools work for CTF challenges?
Yes. Every extractor features auto-detection across multiple algorithms, a 24-plane bit-plane viewer, CTF flag highlighting (e.g. FLAG{...}), entropy analysis, and a downloadable forensic JSON report. StegSolve Online and the LSB Extractor are purpose-built as stego online CTF tools.
Are these steganography tools completely free?
Yes — every tool is 100% free with no account, no subscription, and no usage limits. All processing happens in your browser using WebAssembly and the Web Crypto API. No files are ever uploaded to a server.