ShadowCat
file transfer through QR Codes in a Browser
Details
- External ID
- 48234287
- Source
- HN
- Company
- —
- Product
- ShadowCat
- Website domain
- github.com
- Launched
- May 22, 2026
- Cohort
- —
- Upvotes
- 168
- Upvotes percentile
- 0.9507269789983845
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Enrichment
- Theme
- web development and browser utilities
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- B2C
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- file transfer via qr codes
- Manually corrected
- False
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 — 739 launches clear the similarity bar, closest 8 shown.
Attention rank: #34 of 740 (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 0.63
- Popcorn · hn · 2026-08-06 · 11 upvotes · similarity 0.53
- EchoRelay · hn · 2026-06-30 · 5 upvotes · similarity 0.51
- pi-jev · github · 2026-09-18 · 11 upvotes · similarity 0.50
- snapdrop · github · 2026-09-14 · 17 upvotes · similarity 0.48
- Altersend · hn · 2026-06-05 · 14 upvotes · similarity 0.48
- FastLog: 1.4 GB/s text file analyzer with AVX2 SIMD · hn · 2026-02-07 · 5 upvotes · similarity 0.47
- Beautiful QR Codes · hn · 2026-07-14 · 20 upvotes · similarity 0.47
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a dev tools tool for Sales yet.