Tools for web developers
Format, minify and validate code right in your browser. No server, no data upload.
Popular tools
Tools →HTML Formatter & Minifier
Format and minify HTML code online. Fully processed in your browser, nothing sent to a server.
JSON Formatter & Validator
Format, validate and minify JSON online in your browser.
Base64 Encode/Decode
Base64 encode and decode in your browser, with correct handling of Cyrillic and emoji.
Regex Tester
Test a regular expression against sample text in your browser, with match highlighting.
Meta Tags Generator
Generate title, description, Open Graph, and Twitter Card tags for a page.
JWT Decoder
Decode a JWT's header and payload in your browser. Signature is NOT verified.
Learn and practice HTML
HTML Editor Online
An online HTML editor with syntax highlighting, line numbers, and a live preview. No sign-up, no server.
Learn HTML
A free interactive HTML course for beginners — with code examples and practical exercises.
HTML Practice
Practical HTML exercises for self-study and classroom practice.
Reference
HTML →The <a> tag
The href, target, rel, and download attributes of the <a> tag, with examples.
<img>The <img> tag
The src, alt, loading, and srcset attributes of the <img> tag, with examples.
<form>The <form> tag
The action, method, and enctype attributes of the <form> tag, with an example.
<input>The <input> tag
Types and attributes of the <input> tag: type, name, value, required, pattern.
Snippets
Snippets →Center an element horizontally and vertically
The simplest modern way to center a block using flexbox.
htmlResponsive image
How to give the browser several image variants for different screen sizes.
cssSticky header
CSS position:sticky for a header that stays visible while scrolling.
cssResponsive table
An overflow-x:auto wrapper for horizontal table scrolling on narrow screens.
Your code stays with you
Every tool on this site processes your code entirely in your browser. Nothing you type or upload is ever sent to a server.