ShadowCat
file transfer through QR Codes in a Browser
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HN · launched May 22, 2026 · 168 upvotes (top 5%) · 1 view
Niche: file conversion and transfer utilities · 152 launches, 7 in the last 7 days ▼ -30% · Explore this niche →
Category and tags
- Horizontal
- Communication
- B2C
- Not AI
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 152 launches in file conversion and transfer utilities →
Could you build this?
Yes Transferring files via dynamic QR codes is entirely achievable with standard JavaScript libraries for chunking binary files, rendering QR frames onto a `<canvas>`, and reading them with the device camera via `getUserMedia`.
Discussion
20 comments analyzed.
Competitors mentioned: Bluetooth file transfer, Cloud-based file transfer, Traditional QR codes
Concerns raised: Memory access bugs in WASM stream decoder, iPhone native camera app doesn't reassemble chunks, Low bandwidth at distance (0.1 B/s per pixel), Security vulnerabilities from side-channel attacks via light measurement, Rolling shutter limitations
Feature requests: Support starting chunk reception at any point without requiring total chunk amount upfront, Use 1D code variant with high FPS to bypass rolling shutter for higher bandwidth, Encode data in UV channels for 50% bandwidth improvement, Clearer progress/recovery UI showing which chunks received
Competitors
Other products that read as similar to this one : 2106 launches clear the similarity bar, closest 8 shown.
Attention rank: #99 of 2107 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 204 days after the earliest competitor.
- qr · github · 2026-09-15 · 8 upvotes · similarity 0.64
- Popcorn · hn · 2026-08-06 · 11 upvotes · similarity 0.55
- RingTool · github · 2026-11-01 · 14 upvotes · similarity 0.53
- waltr-desktop · github · 2026-11-10 · 102 upvotes · similarity 0.53
- EchoRelay · hn · 2026-06-30 · 5 upvotes · similarity 0.53
- FLEX-Download-Manager · github · 2026-10-25 · 72 upvotes · similarity 0.53
- File-Browser · github · 2026-10-12 · 17 upvotes · similarity 0.53
- hop · github · 2026-10-27 · 22 upvotes · similarity 0.53
The niche, labels, vibe code rating and competitor comparison on this page are analysis by Nicheloom. If you use them, please credit nicheloom.com. How you may use our data.