40+ Free Developer Tools

Make your work easier

Fast, private, and easy-to-use tools for developers. All tools run locally in your browser. No data is sent anywhere.

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Tool Categories

Browse tools by category — find exactly what you need

Encoding

3 tools

Base64 Converter

Encode/decode Base64

URL Encode/Decode

URL encode/decode text

HTML Entities

HTML entity encode/decode

Generators

6 tools

UUID Generator

Generate UUID v4

QR Code Generator

Generate QR codes

Lorem Ipsum

Generate placeholder text

Password Generator

Create secure passwords

Nano ID Generator

Generate compact unique IDs
A a

Slug Generator

Create URL-friendly slugs

Colors & Design

4 tools

Color Picker

HEX/RGB/HSL converter

CSS Gradient

Create gradient CSS

Color Contrast Checker

Check WCAG contrast ratios

Color Palette Generator

Generate harmonious color palettes

Data Converters

6 tools

JSON Formatter

Format, validate, minify JSON

Timestamp Converter

Unix timestamp converter

Hash Generator

MD5, SHA-1, SHA-256
01 10 11 02 A1 FF

Number Base

Dec/Hex/Bin/Oct converter

JSON ↔ YAML

Convert JSON/YAML

CSV to JSON

Convert CSV data to JSON

Development

7 tools

JWT Decoder

Decode JSON Web Tokens

Regex Tester

Test regular expressions

Diff Checker

Compare text differences

SQL Formatter

Format SQL queries

URL Parser

Parse URL components

HTTP Status Codes

HTTP status code reference

Cron Expression Parser

Parse cron schedule expressions

Text Tools

5 tools
\\ \"

String Escaper

Escape/unescape strings
A a

Text Case

UPPER/lower/CamelCase

Word Counter

Count words, chars, lines

Dedupe Lines

Remove duplicate lines

Markdown Previewer

Preview Markdown in real-time

Network

4 tools

IP Address Lookup

Lookup IP geolocation & ISP
01 10 11 02 A1 FF

My IP Address

Show your public IP address

DNS Lookup

Query DNS records
\\ \"

User Agent Parser

Parse browser user agent

Image Tools

1 tools

Image to Base64

Convert image to Base64 data URI

Security

2 tools

SSL Certificate Checker

Check SSL certificate details

Password Strength Meter

Evaluate password strength

Formatters

3 tools

CSS Formatter

Format & beautify CSS

HTML Formatter

Format & beautify HTML

JavaScript Formatter

Format & beautify JavaScript

Calculators

1 tools
01 10 11 02 A1 FF

PX to REM Converter

Convert PX to REM/EM units

SEO Tools

0 tools

Why Choose Us?

The tools you need, designed the way you want them

100% Private

All processing happens locally in your browser. Your data never leaves your computer.

Lightning Fast

No server roundtrips. No loading spinners. Just instant results every time.

Always Free

No sign ups. No paywalls. No limits. Just tools that work for developers.

Developer Guides

In-depth tutorials to help you get the most out of our tools

JSON Data Debugging Guide

A systematic approach to finding and fixing JSON errors. Covers validation, formatting, JWT debugging, and real-world API workflows.

Web Encoding Explained

Base64, URL encoding, and HTML entities — when to use each, common mistakes, and practical code examples.

Text Processing for Developers

Regex patterns, case conversion, deduplication, and word counting — practical workflows for everyday text tasks.

Latest Articles

In-depth guides and tutorials for developers

Security

Password Security & Hash Algorithms

MD5 vs SHA-256, password hashing best practices, UUIDs, and how to avoid common security mistakes.
Frontend

CSS Colors & Gradients Guide

HEX, RGB, HSL explained. Building color palettes and creating beautiful CSS gradients with practical examples.

Frequently Asked Questions

Got questions? We've got answers.

Are these tools really free?

Yes! All tools are 100% free to use, with no hidden fees, no paywalls, and no sign-up required. We believe essential developer tools should be accessible to everyone.

Is my data safe? Where is it processed?

All processing happens entirely in your browser. Your data never leaves your computer — we don't upload, store, or even see anything you paste into our tools. This also means the tools work offline once the page is loaded.

Do I need to create an account?

Nope! No accounts, no registrations, no email verification. Just open the tool you need and start using it immediately. We hate unnecessary sign-ups as much as you do.

Are there any usage limits?

No limits at all. Use any tool as many times as you want, with any amount of data your browser can handle. Since everything runs locally, the only limit is your computer's performance.

Can I suggest a new tool or feature?

Absolutely! We love hearing from the developer community. You can reach out through our GitHub repository to suggest new tools, report bugs, or even contribute code.

Does this site work on mobile?

Yes! DevTools Hub is fully responsive and works great on desktops, tablets, and mobile phones. All tools are designed with a mobile-first approach so you can be productive on any device.

Ready to get started?

Pick a tool from our collections and start being more productive today

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