Format, minify and validate JSON, HTML, JavaScript, CSS and SQL, right in your browser. Nothing you paste is sent to a server.
Check whether your JSON is valid and see exactly where any error is.
Turn minified or messy JSON into clean, indented, readable JSON.
Make JSON as small as possible without changing the data.
Explore large or nested JSON as a tree you can expand and collapse.
See exactly what changed between two versions of a JSON document.
Find the path to any value in your JSON, or look up a value by its path.
See the structure of an HTML page: headings, links, images, forms and tags.
Catch common accessibility mistakes in your HTML before your users do.
Check the on-page SEO basics of any page from its HTML.
Indent messy or minified HTML so it's easy to read and edit.
Make HTML smaller without changing how the page looks or works.
Each tool is built on a standard, widely used library rather than home-made parsing: Prettier for formatting, Terser for JavaScript minification, CSSO and CSSTree for CSS, html-minifier-terser for HTML, sql-formatter for SQL formatting and node-sql-parser for MySQL and PostgreSQL syntax checks. JSON is checked with the browser's own strict parser, so errors come with a line and column.
Everything runs in your browser. Your code, config files and data are not sent to our servers.
Formatting and minifying use the same tools many build pipelines use, so the output is what you'd expect.
Validators show what went wrong and where, with the line and column.
No account, no limits on use.
Every developer tool runs entirely in your browser. Nothing you paste or upload is sent to our servers.
No. Every developer tool runs in your browser, so your code and data stay on your device.
A validator, formatter, minifier, tree viewer, a compare tool that shows the differences between two JSON documents, and a path finder that gives you the path to any value.
The SQL Formatter supports standard SQL, MySQL, MariaDB, PostgreSQL, SQLite, SQL Server, Oracle and BigQuery. The SQL Validator checks MySQL/MariaDB and PostgreSQL syntax.
On-page basics in the HTML you paste: title and meta description length, a single H1, the mobile viewport tag, image alt text, Open Graph tags, structured data and the canonical tag. Paste the page source, since browsers don't let one site read another site's HTML.
No. Minifiers remove whitespace and comments and shorten names where it is safe; the code behaves the same. Keep your original for editing.
Yes, all of them, with no sign-up and no usage limits.