govalid

High-performance, type-safe validation library for Go with zero allocations

Overview

govalid is a Go package designed to generate type-safe validation code for structs based on markers. It provides a mechanism to apply validation rules directly in the code by marking struct fields with specific markers. The tool processes these markers and generates corresponding validation functions with zero heap allocations.

Key Features

🚀 Zero Allocations: All validators perform zero heap allocations
🔒 Type Safety: Compile-time validation function generation
⚡ High Performance: Up to 45x faster than reflection-based validators
📝 Marker-Based: Simple comment-based validation rules
🔧 Code Generation: Generates optimized validation functions
🎯 Comprehensive: Support for all common validation patterns

Quick Start

Installation

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go install github.com/sivchari/govalid/cmd/govalid@latest

Basic Usage

Define your struct with markers:

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package main

type User struct {
    // +govalid:required
    Name string `json:"name"`
    
    // +govalid:email
    Email string `json:"email"`
    
    // +govalid:gte=18
    Age int `json:"age"`
    
    // +govalid:maxlength=100
    Bio string `json:"bio"`
}

Generate validation code:

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govalid ./...

Use the generated validation:

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func main() {
    user := &User{
        Name:  "Alice",
        Email: "alice@example.com",
        Age:   25,
        Bio:   "Software developer",
    }
    
    if err := ValidateUser(user); err != nil {
        log.Fatal(err)
    }
    
    fmt.Println("User is valid!")
}

Performance Comparison

Validator	govalid	go-playground/validator	Improvement
Required	1.914	85.82	44.8x faster
Email	36.80	630.4	17.1x faster
GT/LT	~1.914	~61.48	32.1x faster
MaxLength	15.58	74.90	4.8x faster
Enum	2.223	N/A (unique to govalid)	govalid exclusive

All benchmarks show 0 allocations for govalid vs 0-5 allocations for competitors

Methodology: 10 runs per benchmark analyzed with benchstat for statistical significance

Supported Validators

String Validators

govalid:required - Required field validation
govalid:minlength=N - Minimum string length (Unicode-aware)
govalid:maxlength=N - Maximum string length (Unicode-aware)
govalid:email - HTML5-compliant email validation
govalid:url - HTTP/HTTPS URL validation
govalid:uuid - RFC 4122 UUID validation

Numeric Validators

govalid:gt=N - Greater than validation
govalid:gte=N - Greater than or equal validation
govalid:lt=N - Less than validation
govalid:lte=N - Less than or equal validation

Collection Validators

govalid:minitems=N - Minimum collection size
govalid:maxitems=N - Maximum collection size

General Validators

govalid:enum=val1,val2,val3 - Enum validation

Why govalid?

🔥 Performance First

Zero allocations: No heap allocations during validation
Compile-time optimization: Generated code is optimized by the Go compiler
Minimal overhead: Direct field access with no reflection

🎯 Developer Experience

Familiar syntax: Similar to popular validation libraries
Type safety: Catch validation errors at compile time
Clear error messages: Descriptive validation error messages

🚀 Production Ready

Extensive test coverage: Comprehensive unit and benchmark tests
Battle tested: Used in production environments
Maintained: Regular updates and improvements

Get Started

Ready to make your Go validation blazingly fast? Check out our Getting Started guide or browse the available validators.

Get Started → View on GitHub →

🚀

Zero Allocations

All validators perform zero heap allocations, making them perfect for high-performance applications.

0 B/op 0 allocs/op

⚡

Blazing Fast

4.8x to 44.2x faster than go-playground/validator with sub-nanosecond performance for simple operations.

1.96ns required 44.2x faster

🔒

Type Safe

Compile-time validation function generation ensures type safety and catches errors early.

Compile-time Type safe

📝

Simple Syntax

Familiar marker-based syntax similar to other validation libraries, easy to learn and use.

// +govalid:required

🎯

Comprehensive

Support for all common validation patterns plus unique features like enum validation.

13 validators Enum support

🔧

Production Ready

Battle-tested with extensive benchmarks and used in production environments.

Battle tested Production ready

Quick Example

See how easy it is to add validation to your Go structs:

1. Define your struct with markers

type User struct {
    // +govalid:required
    // +govalid:minlength=2
    Name string `json:"name"`
    
    // +govalid:email
    Email string `json:"email"`
    
    // +govalid:gte=18
    Age int `json:"age"`
}

2. Generate and use validation

# Generate validation code
govalid .

// Use generated validation
user := &User{
    Name: "Alice",
    Email: "alice@example.com",
    Age: 25,
}

if err := ValidateUser(user); err != nil {
    log.Fatal(err)
}

Performance Comparison

govalid consistently outperforms go-playground/validator across all validation types:

Validator	govalid	go-playground/validator	Improvement
Required	1.96ns	86.59ns	44.2x faster
Email	38.15ns	644.1ns	16.9x faster
Numeric (GT/LT)	~1.97ns	~63ns	32x faster
String Length	~14ns	~75ns	5x faster

View Detailed Benchmarks

Ready to Get Started?

Install govalid and start validating your Go structs with zero allocations and maximum performance.

Get Started View Validators Benchmarks GitHub