Image Steganography
Hide and reveal text inside images online.
Securely embed a text message into an image and decode compatible hidden messages from images directly in your browser.
Upload Carrier Image to Hide Message
Drag & drop your image here · Choose Lossless Image
Image Steganography Online
A fast, confidential, browser-based steganography engine designed to securely conceal text, passwords, and private notes directly inside innocent carrier image files.
Steganography is the practice of hiding a secret message within an ordinary digital file such that an unauthorized observer cannot detect that data is concealed. Unlike cryptography (which scrambles the message to make it unreadable), steganography conceals the very existence of the communication.
ReducerImage combines Least Significant Bit (LSB) spatial modulation with optional 256-bit AES-GCM authenticated encryption and CRC32 data integrity hashing. All operations execute 100% locally in your web browser via the Web Crypto API, guaranteeing zero server uploads.
Steganography Architecture & Security Matrix
Technical overview of the binary header format, LSB modulation, and cryptographic parameters.
| Protocol Parameter | Implementation Standard | Security & Technical Detail |
|---|---|---|
| Protocol Magic | 4 Bytes (`RDST`) | Prevents decoding non-carrier files and false-positive extractions |
| Modulation Method | 1-Bit LSB per RGB Channel | Changes pixel values by ±1 max; 100% imperceptible to human vision |
| Encryption Cipher | AES-GCM (256-bit) | Authenticated encryption with PBKDF2 (100,000 rounds SHA-256) |
| Integrity Hashing | CRC32 Checksum | Detects data corruption, cropping, or post-processing alterations |
| Carrier Support | PNG, Lossless WebP, BMP | Preserves exact pixel bits; excludes lossy JPEG carriers |
Why Lossless PNG is Required for Reliable Steganography
JPEG compression uses lossy Discrete Cosine Transform (DCT) math and chroma subsampling to discard imperceptible color data to reduce file sizes. While effective for photos, this compression alters pixel color values, destroying the exact least-significant bit patterns where hidden messages reside. Always save and share your steganography carrier as a lossless PNG or WebP file.
How LSB Embedding & Extraction Functions
Our dual-layer steganography engine executes in four synchronized phases:
AES-256 Encryption
Derives cryptographic keys using PBKDF2 with a 16-byte random salt and encrypts payload with AES-GCM.
Binary Packaging
Packages magic header, version, payload length, and CRC32 checksum into a structured binary stream.
LSB Modulation
Modifies the least significant bits of red, green, and blue color channels across pixels sequentially.
Verification Round-Trip
Decodes the newly generated image in memory to verify that recovered text exactly matches original input.
How to Hide & Reveal Secret Messages in 8 Steps
Follow this quick workflow to embed confidential messages and decode them anywhere.
Select Mode
Click 'Hide Text' to embed or 'Reveal Text' to extract.
Upload PNG
Choose a clean lossless PNG, WebP, or BMP carrier image.
Type Message
Input secret notes in English, Hindi, Emoji, or Unicode.
Check Capacity
Review live byte meter to ensure carrier has ample space.
Set Password
Optionally enable 256-bit AES-GCM password encryption.
Embed & Verify
Click Hide Message; the engine auto-verifies decoded integrity.
Download PNG
Download the visually identical encoded stego image file.
Reveal & Copy
Upload stego image in Reveal mode and copy decrypted text.
Frequently Asked Questions
Answers to common questions about LSB steganography, capacity limits, encryption, and lossless formats.