Alternatives

Products that do what Validr-1.2 – Fastest Python validation library plus powerful features does

A simple, fast, extensible python library for data validation. New features: * union validator * dynamic dict validator * timedelta validator * enum validator * slug validator * fqdn validator * nested model class GitHub: https://github.com/guyskk/validr Document: https://github.com/guyskk/validr/wiki Usage: https://github.com/guyskk/validr/wiki/Scenario-&-Example

1. 1PA
   PySchemes – A library for validating data structures in Python▲94

   2017 · github.com

2. 2VF
   Valid8r, Functional validation for Python CLIs using Maybe monads▲6

   I built Valid8r because I got tired of writing the same input validation code for every CLI tool. You know the pattern: parse a string, check if it's valid, print an error if not, ask again. Repeat for every argument. The library uses Maybe monads (Success/Failure instead of exceptions) so you can chain parsers and validators: # Try it: pip install valid8r from valid8r.core import parsers, validators # Parse and validate in one pipeline result = ( parsers.parse_int(user_input) .bind(validators.minimum(1)) .bind(validators.maximum(65535)) ) match result: case Success(port): print(f"Using…

   Nov 2025 · github.com

3. 3RS
   Ruby static type checker – proof of concept▲115

   2017 · github.com

4. 4VJ
   validate.js - lightweight JavaScript form validation library▲102

   2011 · rickharrison.github.com

5. 5FU
   Faster UTF-8 validator▲122

   2019 · github.com

6. 6
   JSON Formatter and Validator▲81

   Useful JSON online tools

   2022

7. 7AS
   A Swift implementation of selected parts of Python standard library▲55

   2014 · github.com

8. 8FJ
   FieldVal.js – JavaScript Validation Library▲19

   2015 · minoblog.io

9. 9VD
   Validator.dart – String validation and sanitization library for Dart▲6

   2014 · github.com

10. 10D5
    Dhi – 520x faster data validation for Python, 77x faster for TypeScript▲5

    Hi HN! I built dhi, a data validation library that uses Zig to compile to both native C (Python) and SIMD WASM (TypeScript). Key points: - Drop-in API compatibility with Pydantic (Python) and Zod (TypeScript) - Python: 24.9M validations/sec (520x faster than Pydantic V2) - TypeScript: up to 77x faster than Zod on invalid data - 28KB WASM bundle, zero JS runtime overhead I'd love feedback on the API surface, benchmarks, and real-world integration pain points. If you're curious, the repo has full benchmarks and examples.

    Jan 2026 · github.com

11. 11FV
    Form-validation.js – JavaScript form validation library▲29

    2020 · github.com

12. 12VA
    Validater – a python tool to validate data by schema▲5

    2016 · github.com

13. 13RB
    Rust built open-sourced CLI tool for API specification validation▲23

    2022 · github.com

14. 14CM
    Compiletime macro to auto generate fast validators for TypeScript types▲7

    2020 · github.com

15. 15AC
    A C# library to help you enforce a Given-When-Then structured Unit test▲24

    I always strive to write better, clean and readable code. But I often find unit tests are hard to read, and especially harder to quickly identify what are the important pieces, or even what the test is testing about. So I came up with this lightweight library to help enforce unit tests with a Given-When-Then structure. I hope you find this useful. Any feedback are welcome. https://github.com/cobrakai-lab/Cobrakai.GWTUnit

    2021

16. 16AP
    A Python Libary That Simplifies Data Validation▲8

    2021 · github.com

17. 17FT
    Framework to create linters for Python, YAML, TOML, JSON▲7

    Hi, this is a Python framework I have created to make my life a little easier when creating custom linting rules. Key features: - Quick to use (~20 LOC to create a functioning linter/checker) - Works with different file formats (as in the description) - Supports multiple ignore/noqa directives (per-line ignores, range ignores, whole file, rules choice during runs) - Single check can span all elements of the file or even all files - Works directly with Python's AST - Tutorials and API reference to make users life easier All in all seems to be quite functional for my private (yet)…

    2025 · github.com

18. 18AN
    A new validation library for JavaScript (React, Backbone integration)▲8

    2014 · github.com

19. 19PP
    Powerful Python Pattern Matching Library▲13

    2021 · github.com

20. 20DT
    Deep Type - validate JavaScript objects and arrays using GraphQL▲8

    2015 · github.com

21. 21VJ
    Valib.js - validation library for the browser and Node.js▲7

    2014 · sideralis.org

22. 22AE
    An easy-to-use go library for parsing and validating form data▲5

    2015 · github.com

23. 23CS
    CSV Schema and Validator▲8

    2018 · github.com

24. 24IB
    I built an open-source alternative to TypeForm [MIT]▲7

    An open-source, headless, API-first platform that empowers developers and product teams to create and optimize custom in-app user flows, such as new user onboarding wizards. Tutim library supports multi-step forms, conditional branching, custom validation, l10n, and more – all through a JSON schema and unlimited flexibility through code. Beta release on GitHub (star us!): https://github.com/tutim-io/tutim. Why it's better than other form builders or open-source libraries? - Flexible: Seamlessly integrate Tutim with your design system components, APIs, and your backend. -…

    2023 · github.com

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