Benchmark

Here is the result of readme parse at MB Pro Retina 2013 (2.4 GHz):

npm run benchmark-deps
benchmark/benchmark.mjs readme

Selected samples: (1 of 28)
> README

Sample: README.md (7774 bytes)
> commonmark-reference x 1,222 ops/sec ±0.96% (97 runs sampled)
> current x 743 ops/sec ±0.84% (97 runs sampled)
> current-commonmark x 1,568 ops/sec ±0.84% (98 runs sampled)
> marked x 1,587 ops/sec ±4.31% (93 runs sampled)
Note

CommonMark version runs with simplified link normalizers for more "honest" compare. Difference is ≈1.5×.

As you can see, markdown-it doesn't pay with speed for its flexibility. Slowdown of "full" version caused by additional features not available in other implementations.