- 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 and color depth. For color images, you can hide approximately 3 bits per pixel (1 bit per RGB channel). A 1024×768 image can hold roughly 900KB of data. A 100×100 image holds about 375 bytes. Use the capacity indicator in the tool to verify your image can accommodate your message.
- 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 tool currently supports text messages. However, the underlying LSB steganography technique can hide any binary data (files, images, audio) as long as the target image is large enough to accommodate the data size.
- 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?
- Yes. Once the page loads, all encoding and decoding happens entirely in your browser without any server communication. You can work completely offline.
- 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.
