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: 2.4.11
- Oxfmt: 0.45.0
=========================================
Benchmarking Large Single File
=========================================
Target: TypeScript compiler parser.ts (~540KB)
- 2 warmup runs, 5 benchmark runs
- Copy original before each run
Benchmark 1: prettier
Time (mean ± σ): 1.037 s ± 0.050 s [User: 1.989 s, System: 0.181 s]
Range (min … max): 0.984 s … 1.120 s 5 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 740.7 ms ± 34.5 ms [User: 1183.0 ms, System: 101.9 ms]
Range (min … max): 709.4 ms … 795.6 ms 5 runs
Benchmark 3: biome
Time (mean ± σ): 173.2 ms ± 3.4 ms [User: 147.8 ms, System: 26.5 ms]
Range (min … max): 168.8 ms … 177.6 ms 5 runs
Benchmark 4: oxfmt
Time (mean ± σ): 173.0 ms ± 3.5 ms [User: 207.5 ms, System: 70.5 ms]
Range (min … max): 169.6 ms … 178.1 ms 5 runs
Summary
oxfmt ran
1.00 ± 0.03 times faster than biome
4.28 ± 0.22 times faster than prettier+oxc-parser
5.99 ± 0.31 times faster than prettier
Memory Usage:
prettier: 230.4 MB (min: 222.3 MB, max: 251.0 MB)
prettier+oxc-parser: 172.0 MB (min: 169.9 MB, max: 174.1 MB)
biome: 67.9 MB (min: 67.7 MB, max: 68.3 MB)
oxfmt: 111.0 MB (min: 110.9 MB, max: 111.2 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): 14.653 s ± 0.150 s [User: 25.244 s, System: 1.245 s]
Range (min … max): 14.485 s … 14.993 s 10 runs
Benchmark 2: prettier+oxc-parser
Time (mean ± σ): 12.307 s ± 0.170 s [User: 16.640 s, System: 0.683 s]
Range (min … max): 11.964 s … 12.463 s 10 runs
Benchmark 3: biome
Time (mean ± σ): 1.288 s ± 0.113 s [User: 4.381 s, System: 0.325 s]
Range (min … max): 1.239 s … 1.606 s 10 runs
Benchmark 4: oxfmt
Time (mean ± σ): 403.1 ms ± 3.0 ms [User: 894.3 ms, System: 299.3 ms]
Range (min … max): 397.9 ms … 407.1 ms 10 runs
Summary
oxfmt ran
3.20 ± 0.28 times faster than biome
30.53 ± 0.48 times faster than prettier+oxc-parser
36.35 ± 0.46 times faster than prettier
Memory Usage:
prettier: 414.9 MB (min: 379.7 MB, max: 558.0 MB)
prettier+oxc-parser: 324.3 MB (min: 315.2 MB, max: 337.2 MB)
biome: 71.5 MB (min: 68.8 MB, max: 75.5 MB)
oxfmt: 140.6 MB (min: 135.8 MB, max: 146.4 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): 41.310 s ± 0.194 s [User: 52.302 s, System: 2.507 s]
Range (min … max): 41.111 s … 41.499 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 12.845 s ± 0.085 s [User: 46.419 s, System: 3.671 s]
Range (min … max): 12.748 s … 12.910 s 3 runs
Summary
oxfmt ran
3.22 ± 0.03 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 1148.1 MB (min: 1145.4 MB, max: 1152.9 MB)
oxfmt: 553.0 MB (min: 492.8 MB, max: 601.5 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): 59.772 s ± 0.292 s [User: 70.835 s, System: 3.016 s]
Range (min … max): 59.438 s … 59.982 s 3 runs
Benchmark 2: oxfmt
Time (mean ± σ): 6.418 s ± 0.049 s [User: 22.892 s, System: 1.679 s]
Range (min … max): 6.362 s … 6.450 s 3 runs
Summary
oxfmt ran
9.31 ± 0.08 times faster than prettier+oxc-parser
Memory Usage:
prettier+oxc-parser: 655.7 MB (min: 648.6 MB, max: 659.4 MB)
oxfmt: 355.8 MB (min: 337.4 MB, max: 379.3 MB)
Full features benchmark complete!
=========================================
All benchmarks complete!
=========================================
