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Show HN: ShadowCat – file transfer through QR Codes in a Browser

6.3 relevance
Score Breakdown
technical depth
7
novelty
8
actionability
6
community
4
strategic
3
personal
7

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Novel technical tool, open source, file transfer via QR.

Open Source github.com
Single file optical file transfer using a browser. Contribute to unprovable/ShadowCat development by creating an account on GitHub.
Summary

ShadowCat is a fully offline, single-file HTML page that transfers files between devices by encoding data into QR codes displayed at configurable FPS and ECC levels, with chunk sizes up to ~500 characters yielding ~0.83 KB/s raw throughput. The receiver reconstructs the file from multiple cycles, deduplicating chunks and verifying CRC, and requires HTTPS or localhost for camera access—ideal for old phones with working cameras but broken radios.

Author

unprovable