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: 2.4.9
- Oxfmt: 0.43.0
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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 ± 0.063 s [User: 2.061 s, System: 0.176 s]
Range (min … max): 1.014 s … 1.134 s 5 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 704.9 ms ± 14.4 ms [User: 1124.4 ms, System: 106.9 ms]
Range (min … max): 683.1 ms … 721.8 ms 5 runs
Benchmark 3: biome
Time (mean ± σ): 164.6 ms ± 1.2 ms [User: 136.1 ms, System: 29.0 ms]
Range (min … max): 163.3 ms … 166.1 ms 5 runs
Benchmark 4: oxfmt
Time (mean ± σ): 163.5 ms ± 5.7 ms [User: 196.4 ms, System: 77.5 ms]
Range (min … max): 157.3 ms … 170.2 ms 5 runs
Summary
oxfmt ran
1.01 ± 0.04 times faster than biome
4.31 ± 0.18 times faster than prettier+oxc-parser
6.63 ± 0.45 times faster than prettier
Memory Usage:
prettier: 236.3 MB (min: 219.6 MB, max: 249.1 MB)
prettier+oxc-parser: 171.5 MB (min: 168.6 MB, max: 174.2 MB)
biome: 69.4 MB (min: 67.7 MB, max: 70.9 MB)
oxfmt: 110.0 MB (min: 109.9 MB, max: 110.1 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): 14.520 s ± 0.164 s [User: 24.868 s, System: 1.260 s]
Range (min … max): 14.205 s … 14.720 s 10 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 12.127 s ± 0.115 s [User: 16.470 s, System: 0.677 s]
Range (min … max): 11.964 s … 12.319 s 10 runs
Benchmark 3: biome
Time (mean ± σ): 1.256 s ± 0.003 s [User: 4.310 s, System: 0.437 s]
Range (min … max): 1.253 s … 1.260 s 10 runs
Benchmark 4: oxfmt
Time (mean ± σ): 392.1 ms ± 1.4 ms [User: 855.9 ms, System: 306.3 ms]
Range (min … max): 389.5 ms … 394.1 ms 10 runs
Summary
oxfmt ran
3.20 ± 0.01 times faster than biome
30.93 ± 0.31 times faster than prettier+oxc-parser
37.03 ± 0.44 times faster than prettier
Memory Usage:
prettier: 409.9 MB (min: 372.2 MB, max: 490.8 MB)
prettier+oxc-parser: 319.7 MB (min: 311.5 MB, max: 324.1 MB)
biome: 71.6 MB (min: 69.3 MB, max: 77.6 MB)
oxfmt: 138.5 MB (min: 131.9 MB, max: 147.5 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): 41.576 s ± 0.139 s [User: 52.851 s, System: 2.523 s]
Range (min … max): 41.464 s … 41.732 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 13.075 s ± 0.107 s [User: 46.563 s, System: 3.780 s]
Range (min … max): 12.952 s … 13.140 s 3 runs
Summary
oxfmt ran
3.18 ± 0.03 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 1142.6 MB (min: 1137.1 MB, max: 1146.4 MB)
oxfmt: 549.9 MB (min: 533.3 MB, max: 579.4 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): 59.562 s ± 0.122 s [User: 70.320 s, System: 3.074 s]
Range (min … max): 59.442 s … 59.687 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 6.266 s ± 0.017 s [User: 22.277 s, System: 1.771 s]
Range (min … max): 6.249 s … 6.283 s 3 runs
Summary
oxfmt ran
9.51 ± 0.03 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 656.8 MB (min: 649.7 MB, max: 661.8 MB)
oxfmt: 336.0 MB (min: 330.9 MB, max: 339.8 MB)
Full features benchmark complete!
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All benchmarks complete!
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