Is the Regex Tester private?

The pattern and test text stay in your browser.

What can I use the Regex Tester for?

Parser drafts, Log checks, Validation patterns are common uses. The tool runs in your browser so it is suitable for quick checks and sensitive snippets.

Does HappyFormatter store Regex Tester input?

No. HappyFormatter's utility tools process pasted input in the browser tab and do not store it on a server.

HappyFormatter Local code tools

Browse tools

Private browser utility

Regex Tester

Test JavaScript regular expressions locally in your browser and inspect matches without uploading sample text.

What this tool is good for

Test JavaScript-compatible regular expressions.

Use flags such as g, i, m, s, u, and y.

List match indexes and captured groups.

Web

5 families

HTML

Markup

Format HTML

CSS

Stylesheet

Format CSS Minify CSS

JavaScript

Browser script

Format JavaScript Minify JavaScript Format with Biome Minify with Biome

TypeScript

Typed script

Format TypeScript Minify TypeScript Format with Biome Minify with Biome

SCSS

Stylesheet

Format SCSS Minify SCSS

Data

7 families

JSON

Structured data

Format JSON Minify JSON

XML

Structured markup

Format XML Minify XML

YAML

Config data

Format YAML

TOML

Config data

Format TOML

SQL

Query language

Format SQL

Proto

Schema

Format Proto

Markdown

Document

Format Markdown

Runtime

7 families

Python

Application code

Format Python Format with Ruff

PHP

Server script

Format PHP Format with Mago

Go

Application code

Format Go

Dart

Application code

Format Dart

Java

Application code

Format Java

Lua

Script

Format Lua

Rust

Systems code

Format Rust

Systems

5 families

C

Native source

Format C

C++

Native source

Format C++

C#

.NET source

Format C#

Objective-C

Apple source

Format Objective-C Format Objective-C++

Zig

Systems code

Format Zig

Utilities

5 families

JSON Tools

JSON

JSON Viewer JSON Sort Keys JSON Diff

Web Encoding Tools

Web

Base64 Encode/Decode Regex Tester URL Encoder/Decoder

Data Converters

Converters

JSON to YAML YAML to JSON JSON to CSV XML to JSON

Security Utilities

Security

JWT Decoder Hash Generator

Color Tools

Colors

Color Converter