Rust Parsing Benchmarks

This repo tries to assess Rust parsing performance.

crate	parser type	action code	integration	input type	precedence	parameterized rules	streaming input
chumsky	combinators	in source	library	&str, &[u8], custom	pratt	Yes	Yes
combine	combinators	in source	library	&str	?	?	?
grmtools	CFG	in grammar	library	?	?	?	?
lalrpop	LR(1)	in grammar	build script	&str	none	Yes	No
lelwel	LL(1)	in grammar	build script	&str	pratt	Yes	No
logos	lexer	in source	proc macro	&str, &[u8]	?	?	?
nom	combinators	in source	library	&str, &[u8], custom	pratt	Yes	Yes
parol	LL(k)/LALR(R)	in grammar	build script	&str	none	?	No
peg	PEG	in grammar	proc macro (block)	&str, &[T], custom	climbing	Yes	No
pest	PEG	external	proc macro (file)	&str	climbing	No	No
winnow	combinators	in source	library	&str, &[T], custom	none	Yes	Yes
yap	combinators	in source	library	&str, &[T], custom	none	Yes	?

Formerly, we compared:

• pom: lack of notoriety

Results

Name	Overhead (release)	Build (debug)	Parse (release)	Downloads	Version
null	0 KiB	217ms	4ms	-	-
grmtools	2,623 KiB	12s	174ms		v0.13.10
chumsky	117 KiB	4s	31ms		v0.10.1
combine	184 KiB	4s	50ms		v3.8.1
lalrpop	1,527 KiB	12s	38ms		v0.22.1
lelwel	148 KiB	5s	10ms		v0.8.0
logos	90 KiB	5s	21ms		v0.15.0
nom	94 KiB	3s	65ms		v8.0.0
parol	1,718 KiB	14s	239ms		v3.0.1
peg	84 KiB	2s	22ms		v0.8.5
pest	130 KiB	6s	62ms		v2.8.0
serde_json	59 KiB	3s	15ms		v1.0.140
winnow	75 KiB	2s	29ms		v0.7.8
yap	65 KiB	499ms	33ms		v0.12.0

System: Linux 6.8.0-58-generic (x86_64), rustc 1.86.0 (05f9846f8 2025-03-31) w/ -j 8

Note:

• For more "Parse (release)" comparisons, see parser_benchmarks
• Parsers have not been validated and might have differing levels of quality (#5)

Running the Benchmarks

$ ./bench.py
$ ./format.py