What is XML?
A plain-English definition, and the tools that work with it.
XML (eXtensible Markup Language) is a text format that stores data in nested, custom tags, like HTML but for arbitrary data rather than web pages. It's used for configuration, data exchange, sitemaps and document formats, prized for being both human-readable and strictly structured.
- XML is verbose but self-describing: every value sits inside a named tag, so the structure is explicit.
- It's stricter than HTML: every tag must be closed and properly nested, or a parser rejects it.
- JSON has largely replaced XML for web APIs, but XML is still everywhere in sitemaps, office documents and enterprise systems.
Tools for XML
Free, private and in your browser. No sign-up.
XML Formatter
Beautify or minify XML in your browser with real well-formedness checking, preserved CDATA, comments, declaration and processing instructions, plus a precise error line: nothing is uploaded.
XML Sitemap Generator
Turn a list of URLs into a valid sitemap.xml with per-URL changefreq, priority and lastmod, validated against the 50,000-URL limit and ready to submit to Google. 100% in your browser.
Sitemap Validator
Paste your sitemap.xml and validate it instantly: well-formed XML, every <url> has a <loc>, the 50,000-URL limit, HTTPS locations and valid changefreq/priority. Catches the errors that make Google reject a sitemap. 100% in your browser.
JSON Formatter
Format, validate and minify JSON in your browser with pinpoint error line + column, jump-to-error, key sorting and live editing: nothing is uploaded.
XML problems we solve
Hit one of these? Here's the fix.
- My website needs an XML sitemapHelp Google find every page. Generate a valid XML sitemap, submit it in Search Console, and link it from robots.txt.
- My JSON is invalid and I can't find the error'Unexpected token' almost always means one stray character. A validator points straight at it so you're not hunting by eye.
Frequently asked questions
Related terms
- JSONJSON (JavaScript Object Notation) is a lightweight, text-based format for structured data, built from key–value pairs and lists. It's the standard way apps and APIs exchange data because it's easy for both humans and machines to read.
- YAMLYAML is a human-friendly data format that uses indentation instead of brackets, making it easy to read and write. It's the go-to for configuration files (CI pipelines, Docker Compose, Kubernetes) where clarity matters more than compactness.
- XML sitemapAn XML sitemap is a file listing a website's URLs so search engines can discover and index them efficiently. It doesn't guarantee ranking, but it helps Google and Bing find every important page (especially on large or new sites) and speeds up indexing of fresh content.
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Problems we solve
Definitions
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