GMSTools DEVELOPER TOOLKIT
Free online developer tools

Work smarter.
Build faster.

Simple tools for everyday development. Format JSON, validate input, compare text, convert colors, and generate useful snippets with free online utilities designed to make everyday tasks faster and easier.

⌕
Popular: JSON Formatter · Base64 · Regex Tester
Explore all tools →How it works
GMSTOOLS / WORKSPACE
const workflow = {
  format: "clean JSON",
  compare: "text changes",
  build: "better tools"
};
✓ Ready when you are.
✦ 10 practical tools
⚡ Works in your browser
{ }JSON Formatter✓JSON Validator⇄Base64 Encoder & Decoder↗URL Encoder & Decoder.*Regex Tester±Text Diff Checker◒CSS Gradient Generator◉Color ConverterM↓Markdown Previewer#UUID Generator
0Practical tools
0Installation needed
⚡Works in your browser
⚡Fast and simple

Get useful results without a complicated workflow.

⌘No installation

Open a tool in your browser and get started.

✓Made for everyday tasks

Practical utilities for developers, students and creators.

The toolkit

Tools that keep work moving.

Pick a task and get a useful result in seconds.

Browse all tools →
{ }

JSON Formatter

Format and beautify JSON so nested data is easier to read.

Open tool ↗
✓

JSON Validator

Check whether your JSON is valid and locate syntax errors.

Open tool ↗
⇄

Base64 Encoder & Decoder

Encode text to Base64 or decode a Base64 string.

Open tool ↗
↗

URL Encoder & Decoder

Encode or decode URL components for safe use in links.

Open tool ↗
.*

Regex Tester

Test a regular expression against sample text in your browser.

Open tool ↗
±

Text Diff Checker

Compare two blocks of text and spot changed lines.

Open tool ↗
◒

CSS Gradient Generator

Create a CSS linear gradient and copy the generated code.

Open tool ↗
◉

Color Converter

Convert a color between HEX, RGB and HSL formats.

Open tool ↗
M↓

Markdown Previewer

Write Markdown and preview a simple rendered version.

Open tool ↗
#

UUID Generator

Generate random UUID v4 identifiers instantly.

Open tool ↗
Designed for clarity

A simpler way to get small jobs done.

Useful utilities without a complicated workflow.

⌁Quick and accessible

Open a tool directly from your browser on desktop, tablet or phone.

⌘Practical outputs

Copy formatted data, generated snippets or comparisons into your workflow.

◈Privacy-aware by design

Included utilities process inputs in your browser; avoid entering passwords or sensitive data.

Have a task to solve?

Browse the toolkit and choose the utility that fits your workflow.

Find your tool →