28 best Python Form Validation libraries in 2023

Python is an indispensable tool for many programmers. With it, you can do away with all the repetitive and tedious work involved with other scripting languages. For a technical process like form validation, with Python, you can ensure that the input text is in the correct format (including both after submitting and inline validation). Hence, when you build an application that accepts user input, you can verify that the data that enters your application is valid, consistent, and secure with various open-source Python libraries.

Here we list down some of those libraries which are useful for form validation. Say, with pydantic, you can define custom data types, parse input data, and then validate it. Using type hints, the library can even coerce input data to the declared types and accumulate errors using ValidationError. pydantic is also easily discoverable given how well it has been documented. Another application, Django-crispy-forms helps you manage Django forms by allowing you to adjust their properties (say, CSS classes, send button, etc.) on the backend. This means you no longer have to rewrite anything in the template. We also have Formspree, which is a backend, API, and email service for HTML and JavaScript forms. It is secure with a honeypot to prevent spam and is the simplest way to embed customized order forms, “Contact Us” forms, and dialogue boxes meant to capture email.