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The purpose of this benchmark is for people who wants to evaluate and compare the performance characteristics of these parsers.

Oxc's parser is at least 3x faster than swc and 5x faster than Biome.

Please note that it is not an apple to apple comparison with Biome.Biome's parserproduces a CST instead of an AST,which requires a lot more work.

Codspeed measures performance by cpu instructions.

Run the following command on your machine for replication.

cargo bench

Generate the table

pnpm ipnpm run table

./memory.sh./files/cal.com.tsxoxc   11.5 mb (1.00x)swc   16.6 mb (1.44x)biome 22.5 mb (1.95x)./files/typescript.jsoxc    68.8 mb (1.00x)swc    92.0 mb (1.34x)biome 117.4 mb (1.70x)

• Usesmimalloc as the global allocator
• Uses the following release profile

[profile.release]opt-level     =3lto           ="fat"codegen-units =1strip         ="symbols"debug         =falsepanic         ="abort"

This is the standard benchmark run in a single thread.

group.bench_with_input(id,&source, |b, source|{    b.iter(||Self::parse(source))});

This uses theiter_with_large_drop function, which does not take AST drop time into account.Notice there is only a 0.3ms difference for oxc, but 7ms difference for swc.

AST drop time can become a bottleneck in applications such as as bundler,where there are a few thousands of files need to be parsed.

group.bench_with_input(id,&source, |b, source|{    b.iter_with_large_drop(||Self::parse(source))});

This benchmark uses the total number of physical cores as the total number of files to parse per bench iteration. For example it parses 6 files in parallel on my Mac i7 6 cores.

This can indicate the existence of global resource contention.

let cpus = num_cpus::get_physical();group.bench_with_input(id,&source, |b, source|{    b.iter(||{(0..cpus).into_par_iter().for_each(|_|{Self::parse(source);});})});