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XML Formatter / Validator

Pretty-print, minify and check whether XML is well-formed, all in your browser.

Related tools

All JSON, XML & formats tools →
YAML Formatter / ValidatorTidy YAML — normalize indentation, convert tabs to spaces and flag tab-indent errors.ISO 8601 Date FormatterTurn any date, time and UTC offset into ISO 8601, RFC 3339, week/ordinal date, RFC 2822, HTTP date and Unix timestamps.SQL FormatterFormat SQL queries with uppercased keywords and clause-by-clause line breaks for readability.XML sitemap generatorGenerate a valid XML sitemap for search engines from a simple list of pages. Each line is a URL — relative paths are resolved against your site URL — and you can append a lastmod date, a changefreq and a priority per row, or set sensible defaults for all of them. Output is standards-compliant urlset XML, ready to publish.JSON to XML converterConvert a JSON object into formatted XML.XML to JSONConvert XML — pasted or from a file — into clean, readable JSON.JSON formatterFormat, beautify or minify JSON — with instant validation.UUID Validator / DecoderValidate UUIDs and decode their version, variant, and the timestamp and MAC a v1 carries.

Open XML Formatter / Validator and you get an answer straight away, with no account to create. You will find it under JSON, XML & formats, with YAML Formatter / Validator and ISO 8601 Date Formatter for the neighbouring cases.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is XML Formatter / Validator?

Pretty-print, minify and check whether XML is well-formed, all in your browser.

When would I actually use this?

Making a machine-generated blob readable, finding the character where a parse fails, and shrinking a file before it ships.

What is the most common mistake?

Assuming valid means correct. A document can parse cleanly and still have the wrong shape for whatever will read it — validation checks the syntax, not the schema.

Is there a tool for the next step?

ISO 8601 Date Formatter is the closest one after this: Turn any date, time and UTC offset into ISO 8601, RFC 3339, week/ordinal date, RFC 2822, HTTP date and Unix timestamps.

What else is worth having open alongside it?

SQL Formatter and XML sitemap generator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Parsing and serialisation follow each format's specification. Key order and whitespace are not semantically meaningful in JSON or YAML, so a reformatted document is equivalent even when the bytes differ.

Further reading

All guides →
ExplainerXML to JSON: Attributes, Repetition, and the Single-Element Array TrapTwo documents that differ only in how many children exist produce two different JSON shapes, and no converter can tell them apart without a schema. Plus what this one really does with attributes, mixed content and whitespace — and the one thing it still cannot record.ExplainerYAML Looks Friendly and BitesYAML is JSON plus a type-inference layer, and the inference is the dangerous part. The same file run through a YAML 1.2 parser and a YAML 1.1 parser: no is a string in one and false in the other, 01234 is 1234 in one and 668 in the other, and 12:30:00 is a number in one of them.ComparisonJSON vs XML: What's the Difference?JSON and XML both store structured data as text, but they trade off differently. Here's how each looks, where each wins, and how to choose.ExplainerWriting a Date as ISO 8601, and Why It Is the Only Unambiguous Format01/02/2026 is 1 February in most of Europe and 2 January in the United States, and nothing in the string says which. ISO 8601 fixes that, sorts as text, and stops being ISO 8601 in four specific places that RFC 3339 rejects.How-toHow to Convert JSON to CSV: Flattening Arrays of Objects into Rows and ColumnsA practical guide to turning a JSON array of objects into a clean CSV file, including how to flatten nested fields and handle the tricky edge cases.ExplainerEscaping a String for JSON: Three Characters Are Mandatory, and One Is a TrapRFC 8259 requires exactly three things to be escaped inside a JSON string. Everything else is optional. The one that actually breaks pipelines is a lone surrogate — legal in JSON text, impossible in UTF-8, and silently replaced the moment your data is written out.