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: 3.8.1
- Biome: 2.4.8
- Oxfmt: 0.42.0
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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): 1.083 s ± 0.015 s [User: 2.096 s, System: 0.203 s]
Range (min … max): 1.073 s … 1.109 s 5 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 755.4 ms ± 7.0 ms [User: 1217.5 ms, System: 111.1 ms]
Range (min … max): 750.1 ms … 767.6 ms 5 runs
Benchmark 3: biome
Time (mean ± σ): 181.9 ms ± 1.3 ms [User: 150.9 ms, System: 31.0 ms]
Range (min … max): 179.9 ms … 183.2 ms 5 runs
Benchmark 4: oxfmt
Time (mean ± σ): 175.3 ms ± 5.6 ms [User: 207.0 ms, System: 88.2 ms]
Range (min … max): 166.1 ms … 181.1 ms 5 runs
Summary
oxfmt ran
1.04 ± 0.03 times faster than biome
4.31 ± 0.14 times faster than prettier+oxc-parser
6.18 ± 0.21 times faster than prettier
Memory Usage:
prettier: 240.9 MB (min: 220.1 MB, max: 265.9 MB)
prettier+oxc-parser: 170.1 MB (min: 168.3 MB, max: 173.3 MB)
biome: 68.3 MB (min: 67.1 MB, max: 71.6 MB)
oxfmt: 107.6 MB (min: 107.4 MB, max: 107.7 MB)
Large single file benchmark complete!
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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): 16.119 s ± 0.211 s [User: 27.005 s, System: 1.915 s]
Range (min … max): 15.738 s … 16.355 s 10 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 13.621 s ± 0.345 s [User: 18.142 s, System: 1.222 s]
Range (min … max): 12.912 s … 13.930 s 10 runs
Benchmark 3: biome
Time (mean ± σ): 1.348 s ± 0.110 s [User: 4.435 s, System: 0.441 s]
Range (min … max): 1.286 s … 1.593 s 10 runs
Benchmark 4: oxfmt
Time (mean ± σ): 416.9 ms ± 8.1 ms [User: 899.9 ms, System: 318.8 ms]
Range (min … max): 410.4 ms … 436.9 ms 10 runs
Summary
oxfmt ran
3.23 ± 0.27 times faster than biome
32.68 ± 1.04 times faster than prettier+oxc-parser
38.67 ± 0.91 times faster than prettier
Memory Usage:
prettier: 404.9 MB (min: 379.7 MB, max: 416.7 MB)
prettier+oxc-parser: 323.2 MB (min: 313.6 MB, max: 330.6 MB)
biome: 70.4 MB (min: 68.7 MB, max: 73.9 MB)
oxfmt: 135.8 MB (min: 130.0 MB, max: 140.1 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): 44.886 s ± 0.702 s [User: 55.624 s, System: 4.118 s]
Range (min … max): 44.154 s … 45.554 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 14.070 s ± 0.264 s [User: 50.201 s, System: 4.196 s]
Range (min … max): 13.783 s … 14.302 s 3 runs
Summary
oxfmt ran
3.19 ± 0.08 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 1144.3 MB (min: 1138.9 MB, max: 1147.1 MB)
oxfmt: 583.8 MB (min: 514.8 MB, max: 639.4 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): 62.823 s ± 0.903 s [User: 67.349 s, System: 11.085 s]
Range (min … max): 62.018 s … 63.799 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 6.635 s ± 0.112 s [User: 23.758 s, System: 1.916 s]
Range (min … max): 6.561 s … 6.764 s 3 runs
Summary
oxfmt ran
9.47 ± 0.21 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 636.2 MB (min: 625.0 MB, max: 645.0 MB)
oxfmt: 331.4 MB (min: 319.4 MB, max: 338.0 MB)
Full features benchmark complete!
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All benchmarks complete!
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