Free online tools for developers and web professionals

Free browser-based tools for developers and web professionals. Fast, private and completely free: everything runs directly in your browser.

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Developer Tools Format, validate, encode and generate — code utilities for everyday work. Text & Productivity Clean, transform, count and generate text in seconds. Image & Design Optimize, convert and create images and colors without uploading anything. Calculators & Converters Fast, accurate everyday calculations with zero frills. Interactive & Fun Take a break with polished mini experiences.

Most popular tools

JSON Formatter & Validator Beautify, minify and validate JSON instantly in your browser.

Regex Tester Test regular expressions live with flags, match highlighting and capture groups.

Base64 Encoder & Decoder Encode text to Base64 or decode Base64 back to text, with full Unicode support.

UUID Generator Generate one or many random UUIDs (v4) with cryptographically secure randomness.

Unix Timestamp Converter Convert Unix timestamps to human dates and back, in your local time zone or UTC.

Color Converter (HEX, RGB, HSL) Convert colors between HEX, RGB, HSL and named CSS colors, with live preview.

CSS Gradient Generator Design linear and radial gradients visually and copy production-ready CSS.

Word & Character Counter Count words, characters, sentences and paragraphs as you type, with reading time.

Recently added

2048 The classic sliding tile puzzle, playable with keyboard, touch or swipe.

Date & Business Days Calculator Calculate date differences, add or subtract time, and count business days.

Unit Converter Convert length, mass, temperature, area, volume, speed and data units instantly.

QR Code Generator Generate QR codes for URLs, text, Wi-Fi and contact data, as PNG or SVG.

XML Sitemap Generator Build a valid XML sitemap from a URL list, for small and medium sites.

Favicon Generator Turn any image into a complete favicon set with the HTML snippet to include it.

For developers

Everyday utilities for writing and debugging code — from JSON and regex to CSS generators.

JSON Formatter & Validator Beautify, minify and validate JSON instantly in your browser.

Regex Tester Test regular expressions live with flags, match highlighting and capture groups.

Base64 Encoder & Decoder Encode text to Base64 or decode Base64 back to text, with full Unicode support.

URL Encoder & Decoder Encode or decode URLs and query strings, component by component or whole links.

UUID Generator Generate one or many random UUIDs (v4) with cryptographically secure randomness.

Hash Generator (SHA-256 & more) Compute SHA-256, SHA-384, SHA-512 and SHA-1 digests of any text, locally.

Unix Timestamp Converter Convert Unix timestamps to human dates and back, in your local time zone or UTC.

Regex Generator Build regular expressions from examples, with ready-made patterns for common cases.

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For webmasters & SEO

Generate slugs, meta tags, structured data and sitemaps — and check accessibility contrast.

SEO Slug Generator Turn any title into a clean, URL-safe, SEO-friendly slug.

Meta Tag Generator Generate title, description, Open Graph, Twitter and robots meta tags from a form.

JSON-LD Structured Data Generator Generate valid JSON-LD (schema.org) for websites, articles, FAQs, products and more.

XML Sitemap Generator Build a valid XML sitemap from a URL list, for small and medium sites.

WCAG Contrast Checker Check text contrast against WCAG 2.2 AA and AAA thresholds, with live preview.

QR Code Generator Generate QR codes for URLs, text, Wi-Fi and contact data, as PNG or SVG.

For content & productivity

Word & Character Counter Count words, characters, sentences and paragraphs as you type, with reading time.

Case Converter Convert text between UPPERCASE, lowercase, Title Case, Sentence case and camelCase.

Markdown ↔ HTML Converter Convert Markdown to sanitized HTML and HTML back to Markdown, safely.

Text Diff Checker Compare two texts and highlight added, removed and changed parts.

Text Cleaner & Normalizer Strip smart quotes, extra spaces, hidden characters and other pasted-text noise.

Duplicate Line Remover Remove duplicate lines from lists, with optional trimming and case sensitivity.

See all text & productivity tools →

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Frequently asked questions

Are all the tools really free?

Yes. Every tool on DevToolbox is free to use, with no registration, no usage limits and no paywalls. The project is designed so that optional advertising slots can be added later without ever putting features behind a paywall.

Is my data sent to your servers?

No. DevToolbox is local-first: text, code and files you paste or upload are processed by your browser and never transmitted. The only network requests the site makes are for the page assets themselves.

Do I need to install anything or create an account?

No. Every tool works directly in a modern browser — Chrome, Firefox, Safari or Edge — on desktop and mobile. There is no account system and nothing to install.

Can I use the tools on my phone or tablet?

Yes. The whole site is responsive and every tool is tested at screen sizes from 320 px phones up to large desktop displays, with touch-friendly controls.

Is it safe to paste confidential text or code?

For tools that process text, the input stays in your browser tab and is not stored on any server. Avoid sharing secrets anyway as a general rule, but for tools marked local-first the processing never leaves your device.

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