Ajv is the fastest JSON Schema validator for Node.js and browser. Ajv supports draft-04/06/07.
Ajv generates code using doT templates to turn JSON Schemas into super-fast validation functions that are efficient for v8 optimization. Currently Ajv is the fastest and the most standard compliant validator according to these benchmarks:
Ajv implements several extensions to JSON Schema specification (e.g., $data reference) and allows users to define their own custom keywords. ajv-keywords defines several useful keywords, some of which will be included in the next versions of JSON Schema specification -
propertyNames is included in draft-06 (soon to be published) and
if/then/else is considered for draft-07.
Because we work directly with the maintainer of Ajv, the Tidelift Subscription ensures any Ajv errors are fixed quickly.
You can learn more about ajv on the Ajv docs and the Ajv repo. You can also check out an interview with Ajv maintainer Evgeny Poberezkin here.