Below are the results of crude benchmarks comparing pydantic to other validation libraries.

Package Version Relative Performance Mean validation time
pydantic 1.0b1 46.5μs
marshmallow 2.15.1 2.9x slower 136.1μs
trafaret 1.2.0 3.3x slower 154.2μs
toasted-marshmallow 2.15.2post1 3.4x slower 159.4μs
django-restful-framework 3.10.3 12.4x slower 577.0μs

See the benchmarks code for more details on the test case. Feel free to suggest more packages to benchmark or improve an existing one.

Benchmarks were run with Python 3.7.4 and the package versions listed above installed via pypi on Ubuntu 18.04.