Benchmarks

Performance is a release gate, not a marketing page. Every selected report keeps the host, toolchain, and OXC identity, corpus hash, raw timing or RSS samples, sampling policy, distributions, and every assertion. Everything below is generated at build time from the reports listed in docs/acceptance/performance-report.json, so this page cannot silently pick up a newer failed or incomplete run.

How to read the results:

• MiB/s is throughput: mebibytes of source processed per second. Higher is better.
• p95 is the nearest-rank 95th percentile of the retained samples. It shows tail behavior, not just the average.
• Ratios like 1.004× divide by the denominator named in that row.
• One chart per gate. Every numeric release gate gets its own small chart with the gate's name on top and a one-line summary under it, including a plain "pass" or "FAIL" word.
• The top strip shows the checked value as a diamond on an axis that starts at zero. The dashed vertical line is the frozen budget, named in the strip's left label, and the lightly shaded area is the failing side of that budget. The release fails if the diamond ever lands in the shaded area.
• The bottom strip zooms in on the retained samples from the selected report, one dot per sample. Its axis is zoomed to the spread, so read its tick labels; it usually covers a much smaller range than the top strip. The solid vertical line is the median sample and the dotted vertical line is the p95 sample.
• Ratio charts. The diamond in the top strip is the asserted ratio, which is the value the release gate checks. The bottom strip shows the raw samples of the two runs that ratio divides, on one shared milliseconds (or MiB) axis, each run with its own median tick. The two runs are sampled independently, so dividing sample pairs would invent data; only the asserted ratio is plotted against the budget.
• Single-value charts. Some gates record exactly one number per report, like cold starts and editor memory. Those charts show only the top strip and say "single measurement per report".
• Hover or focus any table row for the exact result, the budget, the sample count, the median, and the p95.

Three results need extra care:

• The matched CLI lane gives ESLint, official Oxlint, and OXC for TSRX the same byte-identical 1,000-file TSX corpus, one rule, and identical run conditions. The separate mixed-file-types result only compares the product against itself on a different workload.
• The native cold-start ratios compare a direct Rust executable with the official npm launcher, so they are diagnostic, not tool-speed claims.
• The formatter's 16.6 MiB/s floor is a regression threshold derived from an older 1.66 MiB/s measurement on a different corpus, not a like-for-like Prettier comparison. The same-build canonical OXC controls are the comparable overhead measurements.

Noise is handled by a fail-closed rerun policy instead of picking a favorable sample:

• Each invocation creates exactly one fresh report.
• A first report inside the 3% near-threshold band requires exactly two additional fresh reports. Only the assertions that triggered get two-of-three tolerance; everything else must pass in all three.
• Any failure more than 3% beyond its threshold is definitive.
• The representative report is selected by median normalized budget pressure with a stable report-path tie-break, never by picking the fastest run. The aggregate fails if the selected representative is red.

Make the authoritative release decision with:

node tests/acceptance/run-performance.mjs

The individual commands below produce diagnostic raw reports without the aggregate admission, rerun, and selection policy:

cargo run --release --locked -p oxc_tsrx_benchmark -- \
  --assert benchmarks/native-lint/budgets.json
cargo run --release --locked -p oxc_tsrx_format_benchmark -- \
  --assert benchmarks/native-format/budgets.json
node benchmarks/vite/run.mjs
pnpm run benchmark:type-aware
pnpm run benchmark:editor
pnpm run benchmark:comparative

Matched 1,000-file CLI comparison

ESLint, official Oxlint, and OXC for TSRX lint the same byte-identical TSX files with one no-debugger rule, the same explicit file list, zero-diagnostic default output, 5 warmups, and 20 measured processes. Every lane runs through its npm CLI entry point. The ordinary oxlint-tsrx lane imports the exact declared official Oxlint launcher in the same Node process; only the separate mixed-file-types lane enters the native TSRX path. That mixed row is a paired internal workload ratio, not a cross-tool comparison. Report: benchmarks/comparative/results-1784321699288.json (2026-07-17), every budget passed.

Near-threshold adjudication. mixedNoBlowup entered the unchanged 3% band, so the aggregate required exactly 2 additional fresh identity-matched reports. Only triggering assertions receive two-of-three tolerance; every other assertion and invariant must pass in every report. The representative is selected by median normalized budget pressure with a stable report-path tie-break, never by choosing the fastest passing sample. Any failure more than 3% beyond its threshold, or a red selected representative, fails the aggregate. Retained reports: benchmarks/comparative/results-1784321699288.json, benchmarks/comparative/results-1784321719516.json, benchmarks/comparative/results-1784321739730.json.

Native lint

Frozen release gate: throughput, same-build ordinary-path overhead, cold start, memory, and batch invariants. The npm-launcher ratio is a diagnostic boundary, not a speed claim. Report: benchmarks/native-lint/results-1784321646022.json (2026-07-17), every budget passed.

Native format

Frozen release gate: formatter throughput, convergence scaling, memory, and batch invariants. The historical 16.6 MiB/s value is an absolute cross-corpus-derived floor, not a speedup claim. Report: benchmarks/native-format/results-1784321655592.json (2026-07-17), every budget passed.

Near-threshold adjudication. p07_rss_ratio entered the unchanged 3% band, so the aggregate required exactly 2 additional fresh identity-matched reports. Only triggering assertions receive two-of-three tolerance; every other assertion and invariant must pass in every report. The representative is selected by median normalized budget pressure with a stable report-path tie-break, never by choosing the fastest passing sample. Any failure more than 3% beyond its threshold, or a red selected representative, fails the aggregate. Retained reports: benchmarks/native-format/results-1784321650912.json, benchmarks/native-format/results-1784321655592.json, benchmarks/native-format/results-1784321660260.json.

Opt-in type-aware lint

The opt-in TypeScript-Go lane. The default lane stays syntax-only with zero type processes. Report: benchmarks/type-aware/results-1784321661795.json (2026-07-17), every budget passed.

Vite/Vite+ command boundary

Fresh companion processes at the ecosystem seam. Vite build and HMR carry zero OXC for TSRX transforms. Report: benchmarks/vite/results-1784321678410.json (2026-07-17), every budget passed.

Native editor server

Syntax-only local language-server round trips on the retained Markless fixture. Report: benchmarks/editor/results-1784321679056.json (2026-07-17), every budget passed.

Measurement hygiene#

• Harnesses are release-only.
• memory-stats is linked only into benchmark executables, never the distributed CLI.
• Normal source metadata excludes configuration time; aggregate metadata and dedicated configuration lanes report it separately.
• Formatter reports keep scan, projection, canonical parse, canonical format, and checked-lift timing arrays separately.
• Thresholds never change during adjudication.