Open-source alternatives to Govalidator

Any-rule is a multi-platform regular expression tool that provides a curated catalog of over 70 ready-to-use patterns for validating and extracting common data formats. The project separates its static regex collection from editor-specific plugins, allowing the same pattern library to be accessed through VS Code, IntelliJ IDEA, Alfred Workflow, and a web interface. The tool enables keyword-based pattern retrieval, letting users search for the correct regex by typing descriptive terms rather than remembering exact syntax. It covers a broad range of validation needs including email addresses, U

This project is a data validation framework for the Go programming language that enforces integrity by applying declarative constraints to struct fields. It utilizes reflection to inspect data structures at runtime, mapping field-level requirements defined in struct tags to specific validation logic. The library distinguishes itself through its ability to handle complex object graphs by recursively traversing nested structures and slices. It supports context-aware validation, allowing developers to switch between different rule sets for the same data structure based on application state or sp

ow is a type-safe schema validation library for TypeScript that verifies data integrity at runtime. It functions as a runtime validation framework and type guard utility, ensuring that JavaScript values match expected types and schemas before they are processed. The library synchronizes runtime data checks with static TypeScript type definitions, allowing users to extract type definitions directly from validation predicates. This integration enables type narrowing, where a successful validation result refines the variable type for safer usage in the code. The framework uses a chainable API t

Valibot is a modular, type-safe schema library for validating and parsing structural data in TypeScript environments.

Dollar is a functional programming library for Swift that provides a comprehensive toolkit for collection manipulation, string processing, mathematical calculations, and date and time management. It serves as a utility suite for filtering, aggregating, and restructuring arrays and dictionaries. The project implements functional programming patterns such as currying, memoization, and function composition. It also features a chainable wrapper interface that allows multiple data transformations to be applied sequentially before extracting a final result. The library covers a wide range of capab

Carp is a statically typed Lisp compiler that compiles Lisp-like syntax directly to C source code, enabling seamless integration with existing C libraries and low-level system programming. It manages memory deterministically at compile time using ownership tracking and linear types, eliminating garbage collection pauses and runtime overhead while ensuring type safety through an inferred static type system. The language distinguishes itself through compile-time macro expansion and metaprogramming capabilities, allowing code generation and transformation before final binary output. It enforces

is.js is a JavaScript validation library and data type checker. It provides a suite of utilities to verify whether variables are primitives, arrays, functions, or specific object types. The project allows for the implementation of custom validation logic and the use of naming namespaces to override default rules and regular expressions. It covers a broad range of validation capabilities, including numeric arithmetic properties, date and time analysis for relative and absolute ranges, and string format verification for patterns such as emails, URLs, and IP addresses. The library also includes

validator.js is a JavaScript string validation and sanitization library. It provides a set of functions to verify that strings match specific patterns—such as emails, URLs, and alphanumeric formats—and a toolkit for cleaning and transforming text input to remove prohibited characters and trim whitespace. The library includes utilities for standardizing email addresses by lowercasing domains and removing sub-addressing markers. It also functions as an HTML entity escaper, replacing special characters with entities to prevent the browser from executing text as code. The project covers capabili

This PHP assertion library is a runtime data validator used to verify method inputs and outputs. It provides a toolkit for validating data types, numeric ranges, and string patterns during program execution to prevent invalid states. The project serves as a static analysis helper by providing type hints and annotations that improve the accuracy of formal verification tools. It includes a collection validation utility for applying rules across arrays or iterable collections, and a filesystem validation tool to verify path existence and read or write permissions. The library covers a broad ran

async-validator is a JavaScript schema validation library and asynchronous data validation engine. It verifies complex object structures and nested arrays by applying recursive rules and non-blocking, promise-based execution to ensure data integrity. The library functions as both an object constraint validator and a data transformation pipeline. It allows for the sanitization, coercion, and formatting of input values through a sequence of functions that run before and after the primary validation process. The engine covers a range of capabilities including recursive nested validation, the en

This project is a Python implementation of the JSON Schema specification, providing a library for verifying that data instances conform to defined schemas. It serves as a data validation framework capable of validating both the data itself and the schemas against official meta-schemas to ensure structural correctness. The library features a schema reference resolver that maps URIs to definitions, enabling the resolution of internal and remote references for modular schema management. It is designed for extensibility, allowing for the definition of custom keywords, custom type-checking logic,

Hibernate Validator is a reference implementation of the Jakarta Validation specification, serving as a framework for enforcing data integrity across Java applications. It functions as a declarative validation engine that processes object constraints to ensure that application state remains consistent. By utilizing metadata-driven rules, the library validates object properties, method parameters, and nested collections to maintain data standards throughout an application's layers. The library distinguishes itself through its ability to perform static analysis on validation configurations, ide

30 Seconds of Python is a curated collection of short, reusable Python code snippets designed for quick reference and immediate reuse. It provides an interactive browser that lets you explore snippets organized by tags, search across names and descriptions, and copy code to your clipboard with a single click. The collection covers a broad range of common programming tasks, including list and dictionary operations, string formatting and manipulation, date and time calculations, and color format conversion. It also includes utilities for data transformation, such as converting between case styl

sqlean is a collection of SQLite extension libraries implemented as C-based shared libraries. It provides a suite of additional scalar and table-valued functions that expand the native capabilities of the SQLite database engine. The project provides specialized toolsets for cryptography, advanced mathematics, networking, and filesystem access. These include binary hashing and encoding, statistical analysis, IP address validation, and the ability to map CSV files or filesystem paths as virtual tables. The library also includes comprehensive text processing tools such as regular expressions, f

Hamcrest PHP is a declarative assertion framework and matcher library used for unit testing in PHP. It provides a set of flexible matchers to verify object states, data types, and collection contents. The library includes specialized tools for XML verification using XPath expressions to analyze document structures and element content. It also allows for the creation of complex validation rules by combining multiple independent matchers through logical operators. The framework covers a broad range of validation primitives, including string content inspection, numeric comparison, and object pr

Scriban is a .NET text templating engine and embedded scripting language used for dynamic text generation. It functions as an abstract syntax tree manipulation tool and a template parser, allowing for the conversion of scripts into visitable trees for analysis, modification, and rendering. The engine is specifically designed for Native AOT compatibility, utilizing a reflection-free API to execute templates in trimmed environments. It also provides a dedicated parser and conversion system for Liquid templates, enabling the migration and execution of Liquid scripts within .NET. The project cov

Flasgger is a documentation framework for Flask applications that generates OpenAPI specifications and an integrated Swagger UI. It functions as a documentation generator and specification parser that extracts API schemas from route definitions, function docstrings, and external specification files. The tool allows API definitions to be maintained either within the source code using YAML blocks in docstrings or decoupled into standalone YAML files. It provides a browser-based interactive console for testing and exploring API endpoints directly from the web application. Beyond documentation,

Ibis is a portable Python dataframe library and multi-backend query engine that provides a unified interface for executing data transformations across diverse compute engines. It functions as a Python SQL expression compiler and dialect transpiler, allowing users to define data logic once and execute it across cloud warehouses, embedded databases, and distributed clusters without rewriting code. The project distinguishes itself through a database backend abstraction that decouples transformation logic from the underlying execution engine. It enables polyglot data workflows by mixing raw SQL s

Validator.js is a library of pure, stateless functions designed for the validation and sanitization of string data within any JavaScript environment. It provides a modular suite of tools to verify that user-provided information conforms to specific formats, such as emails, URLs, and dates, while simultaneously cleaning untrusted input to mitigate security risks. The library distinguishes itself through a design that avoids platform-specific APIs, ensuring consistent execution across browsers, servers, and edge runtimes. By utilizing a pre-compiled regular expression engine and a pure data tra

This PHP library provides tools for generating and validating universally unique identifiers according to RFC 4122 standards. It implements a generation tool for creating version 1, 3, 4, and 5 identifiers, as well as sequential and Nil UUIDs. The library features specialized capabilities for transforming identifiers between hexadecimal strings, binary bytes, integers, and date objects. It supports the generation of sequential identifiers to improve database indexing and storage performance, as well as deterministic name-based identifiers using MD5 or SHA-1 hashing. The project includes a va

This project is a PHP compatibility layer that implements the native ctype extension functions in pure PHP. It serves as a polyfill to ensure that character type validation remains consistent across different PHP versions and server environments. The library functions as a portability bridge, providing fallback implementations for environments where the native C extension is missing. This allows applications to maintain stability and consistent behavior regardless of the specific hosting platform or server configuration. The codebase focuses on PHP extension polyfilling and cross-platform de

Huma is an OpenAPI REST framework for Go designed for building HTTP services with automatic OpenAPI 3.1 specification generation and JSON Schema validation. It serves as a toolkit for developing REST and RPC APIs with typed inputs and outputs, deriving interactive documentation directly from the source code. The framework distinguishes itself by automating the synchronization between implementation and documentation. It uses a content-negotiation engine to manage multiple serialization formats via client headers and employs a JSON Schema input validator to automatically verify request paramet

fp-ts is a TypeScript library that brings pure functional programming patterns to the language through algebraic data types, type class abstractions, and composable combinators. It provides foundational data types like Option for optional values, Either for typed error handling, and Task for lazy asynchronous computations, all designed to make invalid states unrepresentable and side effects explicit. The library is built on category theory concepts, offering type classes such as Functor, Applicative, Monad, Semigroup, and Monoid with lawful instances for common data structures. The library di

Backbone.validation is a JavaScript library designed to enforce data integrity within Backbone.js models. It provides a framework for defining declarative validation schemas that intercept attribute changes, ensuring that data meets specified business requirements before it is committed to the model. The library distinguishes itself by tightly coupling model-level validation with user interface components. It features an event-driven binding system that monitors model states and automatically triggers interface updates, providing real-time feedback as users interact with forms. This approach

Arrow is a functional programming library for Kotlin that provides tools for implementing data-oriented programming patterns. It serves as a framework for typed error handling, a concurrency toolkit, and a library for the manipulation of immutable data. The project distinguishes itself through specialized capabilities for managing application failures using explicit types instead of exceptions and implementing resilience patterns such as circuit breakers and retry policies for distributed services. It also provides optics to update and query deeply nested immutable data structures without man

Base UI is a headless component library and unstyled framework providing accessible interface primitives. It decouples behavioral logic and state management from the visual layer, allowing developers to implement complex UI patterns while maintaining total control over the final styling. The library implements WAI-ARIA design patterns to ensure all primitives support standard keyboard navigation and screen reader accessibility. It provides a suite of low-level building blocks that handle the internal mechanics of interface elements without bundling any CSS. The framework covers a broad range