- What is image steganography?
- Steganography is the practice of hiding secret information inside images (or other media) so that the hidden data is invisible to casual inspection. Unlike encryption, which scrambles data, steganography hides the existence of the secret message altogether. This tool uses LSB steganography, which modifies the least significant bits of pixel colors — changes so subtle they are imperceptible to human vision.
- How does LSB steganography work?
- LSB (Least Significant Bit) steganography replaces the least important bits of pixel color values (RGB channels) with bits from your secret message. Since these bits have minimal impact on the visual appearance, the modified image looks identical to the original. For example, in an 8-bit color channel (0-255), changing the LSB alters the color by at most 1 in 256, which is imperceptible to human vision.
- How much data can I hide in an image?
- The capacity depends on image dimensions. This tool uses about 3 bits per pixel, then reserves a 32-bit message-length header and may add encryption overhead. A 100x100 image holds about 3,746 bytes before overhead. A 1024x768 image holds about 294,908 bytes, or roughly 288 KiB, before overhead.
- Is steganography secure?
- Steganography provides concealment — hiding the existence of data — but basic LSB steganography (without encryption) is not cryptographically secure. For security, always use the optional password feature, which applies AES-256-GCM encryption to your message before embedding it. This combines concealment (steganography) with cryptography for defense-in-depth.
- What encryption does the password option use?
- The password option encrypts your message using AES-256-GCM (Advanced Encryption Standard with Galois Counter Mode). The password is derived into a cryptographic key using PBKDF2 with 100,000 iterations and SHA-256 hashing. This meets NIST recommendations for password-based key derivation and is resistant to brute-force attacks.
- Can I hide files other than text?
- This page currently supports text messages only. The underlying LSB technique can be adapted for binary files, but this tool's interface is built for entering, encrypting, hiding, decoding, and copying text.
- Is the hidden message detectable?
- Basic LSB steganography is undetectable to casual inspection — the image looks identical to the original. However, sophisticated steganalysis techniques can sometimes detect the presence of hidden data by analyzing pixel statistics. For maximum security, combine steganography with encryption (use the password feature).
- Is my data really private? Do you store images or messages?
- Yes, completely private. All processing happens locally in your browser using the Web Crypto API. Your images and messages never upload to our servers. Once you close the page, no trace of your data remains. We do not store, log, or access any user data.
- Can I use this tool offline?
- All encoding and decoding runs in your browser after the page loads, so images and messages are not uploaded during the workflow. Browser caching behavior can vary, so do not rely on this page as a packaged offline app.
- What image formats are supported?
- PNG and JPG formats are supported. PNG is recommended because it uses lossless compression, which preserves the exact pixel values needed for steganography. JPG uses lossy compression and may corrupt hidden data during compression.
