Vercel engineer builds a new syntax highlighter, benchmarks correctness against Shiki

shuding · x · 2026-09-08

Vercel engineer shuding explains why he built a new syntax highlighter: years of pain with 1) large language grammar bundles, 2) language detection and dynamic loading, 3) bad performance slowing down the main app.

He validates quality by comparing every span type against Shiki — the de facto gold standard using real ASTs — measuring weighted correctness across GitHub's top 25 languages.

Related event: Vercel open-sources gpu-lexer: a 27.5KB WebGPU model for syntax highlighting(7 posts)→

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