PNG Hidden Data & Repair Lab
Inspect pixel bit planes, hide and recover a UTF-8 message, or diagnose and repair specific PNG container errors locally.
Choose a PNG and operation
Still PNG · up to 20 MiB, 4 million pixels and 4,096 pixels per side.
Choose a PNG to begin.
LSB messages are not encrypted. Only fully opaque RGB pixels are used. Resizing, palette reduction or image editing can destroy the message. Other hidden-data formats are not detected. Repair cannot restore missing pixels or damaged compressed data.
Diagnostics & recovered text
File details appear here.
Repair recomputes chunk CRC fields, appends a missing IEND or removes trailing bytes. It then checks structure and bounded decompression. Successful decoding does not prove the pixels are visually correct. The original file stays unchanged.
Using PNG Hidden Data & Repair Lab
Explore PNG pixel bits and perform explicitly limited container repairs without uploading files for processing.
- Choose a still PNG and inspect its structure report.
- Select bit-plane inspection, message embedding/recovery or repair. Enter the relevant settings and process.
- Read the result report, copy recovered text or download the generated PNG. Keep your original file.
Example
Embed a short message into an opaque PNG, download it, reopen it and choose Recover. Inspect bit zero of the red channel to visualize low-bit patterns.
Questions & answers
Is hidden text encrypted?
No. Anyone using a compatible decoder can recover it. This is not a secure channel for secrets.
Which hidden messages can be recovered?
Only this tool’s TSLSB001 UTF-8 format, using one RGB least-significant bit in fully opaque pixels, with a stored length and CRC checksum.
What PNG errors can be repaired?
Chunk CRC fields, a missing final IEND chunk and trailing bytes after IEND. Truncated chunks, missing image data and damaged compressed pixel data are not reconstructed. Recomputing a checksum does not repair the data it covers.
Does export preserve all PNG properties?
Repair preserves retained chunk data. Bit-plane and message exports re-encode decoded 8-bit RGBA and may discard metadata, profiles and higher bit depth.
Can bit patterns prove a file contains hidden data?
No. Normal images can contain patterns too. Bit-plane inspection is a visualization, not a reliable steganography detector.
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