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: 3.9.9
- Biome: 2.5.15
- Oxfmt: 0.72.0
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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): 2.191 s ± 0.009 s [User: 2.221 s, System: 1.220 s]
Range (min … max): 2.181 s … 2.202 s 5 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 1.303 s ± 0.011 s [User: 1.231 s, System: 0.618 s]
Range (min … max): 1.291 s … 1.315 s 5 runs
Benchmark 3: biome
Time (mean ± σ): 131.4 ms ± 1.7 ms [User: 105.1 ms, System: 31.3 ms]
Range (min … max): 129.7 ms … 133.7 ms 5 runs
Benchmark 4: oxfmt
Time (mean ± σ): 68.9 ms ± 3.1 ms [User: 50.6 ms, System: 22.2 ms]
Range (min … max): 65.1 ms … 72.7 ms 5 runs
Summary
oxfmt ran
1.91 ± 0.09 times faster than biome
18.91 ± 0.86 times faster than prettier+oxc-parser
31.80 ± 1.43 times faster than prettier
Memory Usage:
prettier: 332.5 MB (min: 326.5 MB, max: 343.4 MB)
prettier+oxc-parser: 201.3 MB (min: 200.6 MB, max: 202.3 MB)
biome: 62.1 MB (min: 61.6 MB, max: 63.1 MB)
oxfmt: 100.3 MB (min: 100.2 MB, max: 100.3 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): 18.200 s ± 0.455 s [User: 30.916 s, System: 1.418 s]
Range (min … max): 17.613 s … 19.031 s 10 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 14.652 s ± 0.118 s [User: 19.647 s, System: 1.269 s]
Range (min … max): 14.456 s … 14.810 s 10 runs
Benchmark 3: biome
Time (mean ± σ): 1.198 s ± 0.062 s [User: 3.777 s, System: 0.362 s]
Range (min … max): 1.166 s … 1.373 s 10 runs
Benchmark 4: oxfmt
Time (mean ± σ): 339.2 ms ± 2.7 ms [User: 857.6 ms, System: 297.2 ms]
Range (min … max): 335.0 ms … 341.5 ms 10 runs
Summary
oxfmt ran
3.53 ± 0.19 times faster than biome
43.20 ± 0.49 times faster than prettier+oxc-parser
53.66 ± 1.41 times faster than prettier
Memory Usage:
prettier: 492.6 MB (min: 475.6 MB, max: 506.2 MB)
prettier+oxc-parser: 364.7 MB (min: 353.4 MB, max: 387.1 MB)
biome: 171.9 MB (min: 169.2 MB, max: 175.1 MB)
oxfmt: 144.2 MB (min: 135.2 MB, max: 150.0 MB)
JS/TS (no embedded) benchmark complete!
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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): 85.768 s ± 2.023 s [User: 96.102 s, System: 9.255 s]
Range (min … max): 84.439 s … 88.096 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 5.688 s ± 0.044 s [User: 19.690 s, System: 1.960 s]
Range (min … max): 5.642 s … 5.731 s 3 runs
Summary
oxfmt ran
15.08 ± 0.37 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 1709.5 MB (min: 1680.9 MB, max: 1746.5 MB)
oxfmt: 279.6 MB (min: 275.5 MB, max: 284.4 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): 38.564 s ± 3.186 s [User: 50.111 s, System: 3.750 s]
Range (min … max): 34.897 s … 40.655 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 3.814 s ± 0.036 s [User: 13.196 s, System: 1.274 s]
Range (min … max): 3.791 s … 3.856 s 3 runs
Summary
oxfmt ran
10.11 ± 0.84 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 678.6 MB (min: 652.9 MB, max: 699.4 MB)
oxfmt: 214.7 MB (min: 209.6 MB, max: 219.9 MB)
Full features benchmark complete!
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All benchmarks complete!
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