XML Formatter: Format, Beautify and Validate XML Online
This free XML formatter turns messy or one-line XML into clean, indented code you can read. Paste your XML, choose 2 spaces, 4 spaces or tabs, and the beautified result appears at once. It also minifies XML and checks that it is well-formed, with the exact line and column of any error. Everything runs in your browser.
Paste your XML into the box above and select Format. The result is ready in a moment.
Use the toolChecks that the XML is well-formed. It does not validate against an XSD or DTD schema, and it never repairs your XML for you.
Format and minify
Clean indentation, or compact output, in one click.
Exact error position
Line and column of the first error, with a likely fix.
Keeps your data intact
Comments, CDATA, declarations and mixed content stay as written.
Private by design
Your XML never leaves your browser.
Paste XML into the Input pane and select Format. You get clean indented code, plus the exact line and column of any error. Use Minify to compact it and Validate to check well-formedness.
Key Takeaways
- An XML formatter adds line breaks and indentation so the structure is easy to read. It does not change your data.
- Well-formed XML needs one root element, matched and properly nested tags, and quoted attributes.
- This tool checks well-formedness and reports the line and column of the first error. It cannot check an XSD schema.
- Minifying removes whitespace to save space, but it can alter documents that mix text and tags.
- Your XML is processed in your browser and never uploaded, which suits confidential exports.
Format XML Online: Paste, Beautify, Done
Raw XML from an API response, a log file or an export is often a single unbroken line. The formatter reads it, works out the nesting and writes it back with each element on its own line, indented to match its depth.
Nothing is sent to a server. The parsing and formatting happen on your own device, so you can use it on customer records, database exports and internal configuration files.
What Is an XML Formatter?
An XML formatter is a tool that rewrites XML with consistent line breaks and indentation. It is also called an XML beautifier, an XML pretty printer or an XML indenter. All of these terms mean the same thing: making XML easy for a person to read without changing what it says to a computer.
XML, short for Extensible Markup Language, stores and transports data using tags you define yourself. Unlike HTML, which has a fixed set of tags for presenting pages, XML describes data and is strict about structure.
How to Format XML Online
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1STEP 1 Paste your XML into the Input pane, or select Upload to open an .xml file from your device.
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2STEP 2 Choose your indentation: 2 spaces, 4 spaces or a tab.
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3STEP 3 Select Format. The beautified XML appears in the Output pane.
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4STEP 4 If the XML has an error, a message shows the line and column. Fix it in the Input pane and format again.
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5STEP 5 Select Copy, or Download to save the result as an .xml file.
Before and After: What the Formatter Does
Here is what the tool does to a small example. The input is a single line:
Format vs Minify vs Validate
| Action | What it does | Use it when |
|---|---|---|
| Format (beautify) | Adds line breaks and indentation to show the nesting. | You need to read, review or edit XML. |
| Minify | Removes line breaks and indentation to shrink the file. | You are sending XML over a network or storing it compactly. |
| Validate | Checks the XML is well-formed and reports the first error. | Something fails to parse and you need to find out why. |
Formatting and validating run together. If the XML is broken, the tool shows the error instead of guessing what you meant, because a formatter that silently repairs XML can change your data.
Well-Formed vs Valid XML: The Rules Your XML Must Follow
Well-formed XML follows the syntax rules in the W3C XML 1.0 specification. Valid XML is well-formed and also follows the rules of a schema or DTD. This formatter checks the first kind. A document can be well-formed and still be invalid against its schema.
| Rule | What it means |
|---|---|
| One root element | The whole document sits inside a single top-level element. |
| Matched, nested tags | Every start tag has a matching end tag, and tags close in the reverse order they opened. |
| Case sensitive | The names <Item> and <item> are different. The specification states that no case folding is performed. |
| Quoted attributes | Attribute values sit inside single or double quotes, and an attribute name appears only once per tag. |
| Escaped characters | A literal < or & in text must be written as an entity. |
| Valid names | A name starts with a letter, an underscore or a colon, and cannot start with a digit. |
| Declaration first | If present, the XML declaration must be the very first thing in the file. |
The five entities built into XML are < for <, > for >, & for &, " for a double quote and ' for an apostrophe. If you work with HTML character codes as well, our HTML encoder and decoder converts them both ways.
Common XML Errors and How to Fix Them
| Error message or symptom | Likely cause | How to fix it |
|---|---|---|
| Mismatched or unexpected end tag | A closing tag has a different name or case, or tags overlap. | Make each end tag match its start tag exactly and close inner tags first. |
| Extra content at the end of the document | The file has more than one root element. | Wrap everything in a single parent element. |
| Unescaped character in text | A bare & or < appears in a value. | Replace it with & or <, or put the text in a CDATA section. |
| Attribute value must be quoted | An attribute is written as id=5. | Write it as id="5". |
| Duplicate attribute | The same attribute name appears twice in one tag. | Remove one of them. |
| XML declaration not at the start | A space or blank line comes before the declaration. | Delete everything before the opening of the declaration. |
| Invalid name | A tag or attribute name starts with a digit or contains a space. | Rename it, for example <item1> and not <1item>. |
| Comment error | A comment contains a double hyphen. | Remove the -- from inside the comment. |
The tool reports the first error it finds. After you fix it, run it again, because one mistake can hide others behind it.
XML Beautifier Options: Indentation and Line Breaks
Indentation does not change the meaning of data in XML, so use whatever your team prefers. Two spaces keep deeply nested files narrow. Four spaces are easier to scan on large screens. Tabs let each reader set their own width in their editor.
The formatter preserves comments, CDATA sections, processing instructions and the XML declaration. Elements that contain only text stay on one line, which keeps the output compact.
When Formatting Changes Your XML: Mixed Content and Whitespace
Most XML holds data, where whitespace between elements is ignored. Some XML holds text with tags inside it, called mixed content, such as a paragraph with a bold word in the middle. In that case, whitespace can carry meaning, and adding line breaks inside the text can change how it reads.
To protect your text, the formatter leaves mixed content on a single line and does not add whitespace inside it. The same care applies to minifying. If a document depends on whitespace, test the minified version before using it, and look for the xml:space attribute, which tells applications to keep spacing as written. The tool honors xml:space="preserve" and leaves that element untouched.
Run Format, then compare the result with your original using the text compare tool. You should see only whitespace changes. If any text or tag has changed, stop and check the source.
Want to see the difference for yourself? Format your XML above, then copy the result into the compare tool.
Format XML Files: SOAP, RSS, SVG, Sitemaps and More
Many file types are XML under the surface. The same formatter works on all of them, as long as the content is well-formed.
| File type | What it is | Worth knowing |
|---|---|---|
| SOAP and WSDL | Web service messages and descriptions | Responses often arrive on one line, so format them to read them. |
| RSS and Atom feeds | Content feeds for readers and podcasts | A single stray & breaks the whole feed. |
| SVG | Vector images, such as logos and icons | Format an SVG to edit paths and attributes by hand. |
| XML sitemap | A list of URLs for search engines | Starts with a urlset element, holds up to 50,000 URLs and must be UTF-8. |
| Android layouts and config files | App screens and settings | Indentation is purely for people. |
| XHTML, MathML, RDF | XML-based web and science formats | Named as XML languages in the MDN introduction to XML. |
If you write sitemaps by hand, per the sitemaps.org protocol each file is limited to 50,000 URLs and 50 MB uncompressed, and special characters in URLs must be escaped. Our free XML sitemap generator builds a compliant file for you.
How to Format XML in Code and the Command Line
Sometimes you need to format XML inside a program or a script. These are the usual ways.
| Where | How |
|---|---|
| Command line | xmllint --format file.xml prints formatted XML. |
| Python | xml.dom.minidom.parseString(text).toprettyxml(indent=" ") |
| C# | XDocument.Parse(text).ToString() returns indented XML by default. |
| Java | A Transformer with the INDENT output property set to yes. |
| JavaScript | DOMParser and XMLSerializer do not add indentation, so a formatter needs its own code. |
| Editors | Notepad++ and VS Code format XML through a plugin or extension. |
XML Formatter vs JSON Formatter
XML and JSON both store structured data, and many systems use both. XML supports attributes, comments, namespaces and mixed text, which makes it a common choice for documents and enterprise services. JSON is lighter and maps straight onto code, which is why most modern web APIs use it.
If you are working with JSON instead, try our JSON formatter.
Large XML Files and Performance
Because the file is processed in your browser, the limit is your device's memory, not a server cap. Files of a few megabytes format in a moment. For very large files, such as database exports of hundreds of megabytes, the xmllint command line tool is the better choice, since it does not have to hold a browser tab open.
Who Uses an XML Beautifier
- Developers reading API responses, config files and build output.
- QA testers checking the exact structure of SOAP and web service messages.
- SEO teams reviewing XML sitemaps and RSS feeds for broken tags.
- Data analysts opening exports from databases and business tools.
- Students learning how XML nests, which is much easier when it is indented.
- Designers editing SVG files by hand. Word documents are also ZIP files of XML, so the same skill helps there.
Privacy: Your XML Never Leaves Your Browser
XML often holds sensitive material such as customer records, invoices and system settings. This tool does not upload, store or log anything. Close the tab and your data is gone. You can confirm it by opening your browser's network panel while you format: no request carries your text.
FAQs
How do I format XML online?
Paste your XML into the Input pane, choose 2 spaces, 4 spaces or a tab, and select Format. The beautified result appears in the Output pane, ready to copy or download. If the XML has a syntax error, the tool shows the line and column instead, so you can fix the problem and run it again.
What is the difference between well-formed and valid XML?
Well-formed XML follows the basic syntax rules: one root element, matched and nested tags, quoted attributes and escaped special characters. Valid XML is well-formed and also matches a schema or DTD that defines which elements are allowed. This tool checks well-formedness. It does not test a document against an XSD schema.
Can this tool fix broken XML automatically?
No, and that is deliberate. Automatic repair means guessing what you meant, which can change your data without you noticing. Instead, the tool reports the first error with its line and column and explains the likely cause. Fix it in the Input pane, run it again, and repeat until the document passes.
How do I minify XML, and does it change the data?
Select Minify to remove line breaks and indentation between elements. For data-style XML, this does not change the meaning, only the file size. For mixed content, where text and tags are combined, whitespace can matter, so test the minified file before you rely on it. Keep the formatted version as your working copy.
Is it safe to format confidential XML here?
Yes. The formatter runs entirely in your browser, so the XML you paste is not uploaded, stored or logged by WritoryBuzz. That makes it suitable for internal configuration files and exports. As a general habit, still remove passwords, keys and personal data from anything you do not need to format in full.
How do I format XML in Notepad++ or VS Code?
Both editors need an add-on. Notepad++ uses a plugin that offers a pretty print command, and VS Code uses an XML extension that adds Format Document. If you do not want to install anything, paste the XML into this formatter, copy the result and paste it back into your editor.
How large an XML file can I format?
The limit is your browser's memory, not a server limit. Files up to several megabytes format quickly on most computers. For files of hundreds of megabytes, use the xmllint command line tool, which reads files without opening them in a browser. If a very large file makes the tab slow, split it first.
Does formatting XML change my data?
Not for normal data XML. Formatting only adds whitespace between elements, which parsers ignore. The exception is mixed content, where text sits between tags, and the tool leaves that on one line to avoid changing it. To be sure, compare the formatted and original versions with a text compare tool.
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Go back to the formatter, paste your XML and get clean, readable code in one click.
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