Decimen

Decimen moves a file or a text block from one device to another by drawing animated QR codes on the sender's screen and reading them with the receiver's camera. No account, pairing, cloud bucket, or IP path. Limits on the live page: files up to 64 MB, pasted text up to 4 MB. Payload is compressed when it helps and restored with the original filename.

The repo description names the mechanism: fountain-coded animated QR. The decode side is a separate repo (decimen-codec) that builds zxing-cpp to WASM and keeps a tracked fast path once the stream is locked on. Stack is TypeScript, Vite 6, vite-plugin-pwa, Node ≥24. AGPL-3.0-or-later. 6,499 stars on this check — the largest star count in this batch.

The site is explicit about the security model: files are not encrypted; anything on the sending screen is readable by any camera pointed at it. List it as a working offline transfer tool with that caveat in the story, not as a private messenger.