Show HN: SplatHash – A lightweight alternative to BlurHash and ThumbHash

Hacker News · Feb 28, 2026 · Collected from RSS

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SplatHash encodes any image into exactly 16 bytes (a 22-char base64url string) and decodes it back to a 32×32 blurry preview in 0.067 ms. Go, TypeScript, and Python all produce bit-for-bit identical hashes. Columns: original · SplatHash 32×32 · ThumbHash · BlurHash. Regenerate: mise run compare. Install Language Package Docs Go go get github.com/junevm/splathash/src/go src/go/README.md TypeScript / JS npm install splathash-ts src/ts/README.md Python pip install splathash-py src/py/README.md Go is the reference implementation. All others are verified bit-for-bit against it. Benchmarks Go benchmarks on Intel Core i5-9300H (go test -bench=. -benchmem). SplatHash ThumbHash BlurHash Decode 0.067 ms 0.50 ms 6.55 ms Encode 3.53 ms 0.86 ms 445 ms Decode allocs 7 1,168 5 Bytes 16 fixed 25–37 20–25 String 22 chars 34–50 chars 27–30 chars Decode runs on every page load for every user. Encode runs once at upload. Optimize for decode. Raw output BenchmarkEncodeSplatHash-8 303 3530083 ns/op 100760 B/op 29 allocs/op BenchmarkEncodeThumbHash-8 1431 863553 ns/op 1015 B/op 6 allocs/op BenchmarkEncodeBlurHash-8 3 445696421 ns/op 33358234 B/op 8 allocs/op BenchmarkDecodeSplatHash-8 17182 67622 ns/op 29584 B/op 7 allocs/op BenchmarkDecodeThumbHash-8 6559 503366 ns/op 58408 B/op 1168 allocs/op BenchmarkDecodeBlurHash-8 171 6553100 ns/op 547552 B/op 5 allocs/op Comparison Feature SplatHash ThumbHash BlurHash Fixed output size Yes (16 bytes) No No Storable as 128-bit integer Yes No No Perceptual color space (Oklab) Yes No No Spatially localized basis Yes (Gaussians) No No Global weight optimization Yes (Ridge) No No Alpha channel support Yes Yes No Bit-exact cross-language parity Yes No No Configurable quality vs. size No No Yes How It Works Background color + six Gaussian blobs placed by matching pursuit, color-optimized by Ridge Regression, all in Oklab, packed into 128 bits. Full spec: ALGORITHM.md. Development mise install # install Go and Node at pinned versions mise run test # run all tests (Go + TypeScript + Python) mise run bench # Go benchmarks mise run compare # regenerate docs/comparison.png License See LICENSE.