Redundance · iPhone app
Your QR code scans. But how close was it to failing?
Every QR code carries redundancy, so it survives scratches, glare and logos on top. Redundance re-reads every module and shows how much of that safety margin your scan used up.
Coming soon to the App Store
The grades are estimates from a phone camera. They follow the ideas of ISO/IEC 15415,
but Redundance is not a calibrated barcode verifier.
What it does
How much margin is left
Every module is re-read and compared with the ideal symbol rebuilt from the decoded data. You see the codeword errors in each Reed–Solomon block against what that block can correct.
Every technical detail
Version, size, error correction level, mask pattern, block layout, every bitstream segment with its mode and raw bytes, and the codewords in hex.
A grade you can act on
An A–F grade modeled on ISO/IEC 15415 unused error correction and contrast, plus module errors by region and format information bit errors.
See the matrix
The straightened code with overlays for read errors, uncertain modules, regions and blocks. Tap a module to see its codeword, block and bit.
Live while you scan
A quality meter follows the code in the camera. A volume button freezes the reading, and a hint appears when the lens looks smudged.
From any app
Share a screenshot or photo to Redundance and get the full analysis right in the share sheet.
Reads every other code, too
EAN, UPC, ITF-14, Code 128, Code 39, Data Matrix, Aztec, PDF417 and more: check digits, the GS1 organization behind a product number, ISBN for books, and GS1 data such as expiry date, batch and serial number.
Break it on purpose
The Lab generates a code at any error correction level, damages it, and shows the correction at work.
Private by design
Everything runs on your iPhone. No account, no tracking, no network access.
Perfect for
Designers checking a print proof, developers debugging generated codes, packaging and event teams who need codes that scan everywhere, and anyone curious how QR codes really work.
Support
Questions, bugs or ideas: write to [e-mail]. Read the privacy policy.