Comparing execution time and memory usage of Prettier, Biome, and Oxfmt.
# Run all benchmarks
# Automatically setup fixture if not exists
pnpm run bench
# Or explicit benchmark with manual setup
./init.sh
node ./bench-large-single-file/bench.mjs
node ./bench-js-no-embedded/bench.mjs
node ./bench-mixed-embedded/bench.mjs
node ./bench-full-features/bench.mjs- Each formatter runs on the exact same codebase state (git reset between runs)
- Times include both parsing and formatting of all matched files
- Memory measurements track peak resident set size (RSS) during execution
- I intended to bench checker.ts, but it appears to be running for a very long time or stuck with 100% CPU.
- Test Data:
- Methodology:
- Multiple warmup runs before measurement
- Multiple benchmark runs for statistical accuracy
- Git reset before each run to ensure identical starting conditions
- Memory usage measured using GNU time (peak RSS)
- Local binaries via
./node_modules/.bin/
- Prettier: 3.8.3
- Biome: 2.4.16
- Oxfmt: 0.54.0
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Benchmarking Large Single File
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Target: TypeScript compiler parser.ts (~540KB)
- 2 warmup runs, 5 benchmark runs
- Copy original before each run
Benchmark 1: prettier
Time (mean ± σ): 1.086 s ± 0.081 s [User: 2.061 s, System: 0.183 s]
Range (min … max): 1.011 s … 1.177 s 5 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 711.5 ms ± 8.0 ms [User: 1138.6 ms, System: 104.9 ms]
Range (min … max): 697.2 ms … 715.6 ms 5 runs
Benchmark 3: biome
Time (mean ± σ): 165.5 ms ± 1.5 ms [User: 140.2 ms, System: 30.5 ms]
Range (min … max): 164.3 ms … 167.8 ms 5 runs
Benchmark 4: oxfmt
Time (mean ± σ): 157.3 ms ± 4.1 ms [User: 187.4 ms, System: 68.5 ms]
Range (min … max): 153.0 ms … 163.7 ms 5 runs
Summary
oxfmt ran
1.05 ± 0.03 times faster than biome
4.52 ± 0.13 times faster than prettier+oxc-parser
6.90 ± 0.55 times faster than prettier
Memory Usage:
prettier: 239.2 MB (min: 224.7 MB, max: 255.6 MB)
prettier+oxc-parser: 175.5 MB (min: 174.0 MB, max: 178.5 MB)
biome: 67.5 MB (min: 65.9 MB, max: 69.0 MB)
oxfmt: 104.5 MB (min: 104.5 MB, max: 104.6 MB)
Large single file benchmark complete!
=========================================
Benchmarking JS/TS (no embedded)
=========================================
Target: Outline repository (js/ts/tsx only)
- 3 warmup runs, 10 benchmark runs
- Git reset before each run
Benchmark 1: prettier
Time (mean ± σ): 15.619 s ± 0.173 s [User: 26.680 s, System: 1.345 s]
Range (min … max): 15.363 s … 15.866 s 10 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 13.390 s ± 0.242 s [User: 17.958 s, System: 0.723 s]
Range (min … max): 13.125 s … 13.710 s 10 runs
Benchmark 3: biome
Time (mean ± σ): 1.365 s ± 0.004 s [User: 4.812 s, System: 0.377 s]
Range (min … max): 1.359 s … 1.369 s 10 runs
Benchmark 4: oxfmt
Time (mean ± σ): 432.7 ms ± 3.2 ms [User: 955.6 ms, System: 343.7 ms]
Range (min … max): 428.2 ms … 439.1 ms 10 runs
Summary
oxfmt ran
3.15 ± 0.02 times faster than biome
30.94 ± 0.60 times faster than prettier+oxc-parser
36.09 ± 0.48 times faster than prettier
Memory Usage:
prettier: 413.7 MB (min: 387.2 MB, max: 440.9 MB)
prettier+oxc-parser: 336.4 MB (min: 322.8 MB, max: 355.7 MB)
biome: 72.6 MB (min: 70.1 MB, max: 74.5 MB)
oxfmt: 139.0 MB (min: 134.6 MB, max: 143.0 MB)
JS/TS (no embedded) benchmark complete!
=========================================
Benchmarking Mixed (embedded)
=========================================
Target: Storybook repository (mixed with embedded languages)
- 1 warmup runs, 3 benchmark runs
- Git reset before each run
Benchmark 1: prettier+oxc-parser
Time (mean ± σ): 44.349 s ± 0.209 s [User: 55.530 s, System: 2.622 s]
Range (min … max): 44.201 s … 44.588 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 13.782 s ± 0.087 s [User: 47.788 s, System: 3.836 s]
Range (min … max): 13.708 s … 13.878 s 3 runs
Summary
oxfmt ran
3.22 ± 0.03 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 1165.3 MB (min: 1162.1 MB, max: 1168.8 MB)
oxfmt: 539.3 MB (min: 457.9 MB, max: 631.3 MB)
Mixed (embedded) benchmark complete!
=========================================
Benchmarking Full features
=========================================
Target: Continue repository (full features)
- 1 warmup runs, 3 benchmark runs
- Git reset before each run
Benchmark 1: prettier+oxc-parser
Time (mean ± σ): 35.149 s ± 0.235 s [User: 46.733 s, System: 1.623 s]
Range (min … max): 34.905 s … 35.373 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 5.178 s ± 0.164 s [User: 17.665 s, System: 1.535 s]
Range (min … max): 4.994 s … 5.310 s 3 runs
Summary
oxfmt ran
6.79 ± 0.22 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 666.9 MB (min: 656.2 MB, max: 674.9 MB)
oxfmt: 308.0 MB (min: 286.7 MB, max: 330.8 MB)
Full features benchmark complete!
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All benchmarks complete!
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