Corrupt an XML File Online
Corrupt an .xml file online for free. Breaks the declaration, tag nesting and encoding so XML parsers reject the document as not well-formed.
- No upload
- No size limit
- No sign-up
Corrupt your XML file
Tuned for .xml, .xsd, .rss, .plist, and works with every other format too.
Why XML files are hard to corrupt properly
XML parsers are strict about well-formedness but tolerant about a great deal else. The reliable way to break an XML document is to attack the three things every parser checks first: the declaration, the encoding, and the balance of the tag tree.
What this tool destroys
- The XML declaration. The opening
<?xml version…?>processing instruction is destroyed, so encoding and version cannot be established. - Tag balance. Angle brackets and tag names are overwritten throughout, leaving elements permanently unclosed.
- Encoding validity. Invalid UTF-8 sequences make the document fail before the parser reaches the grammar.
- The root element. The closing bytes are destroyed, so the document root is never terminated.
What you will see afterwards
| Application | Behaviour |
|---|---|
| Browsers | "This page contains the following errors: not well-formed" with the offending line highlighted. |
Python ElementTree | Raises ParseError: not well-formed (invalid token). |
| Java / .NET parsers | Throw SAXParseException or XmlException on the first token. |
| XML editors | Refuse to load or open the file in plain-text mode with errors flagged. |
Common reasons people do this
- Testing an XML ingestion endpoint against malformed input.
- Verifying that a SOAP or RSS consumer surfaces parse failures properly.
- Checking a configuration loader refuses a damaged file rather than starting with defaults.
- Producing not-well-formed fixtures for a conformance test suite.
How to corrupt a XML file
- Drop your .xml file onto the box above, or click to browse.
- Leave the level on Standard unless you want partial damage (Light) or need to defeat recovery software (Heavy).
- Press Corrupt file. Processing happens on your device, so it finishes almost immediately.
- Download the result. It keeps the original filename and byte length by default.
XML FAQ
Does this break XML schema validation too?
It never gets that far. Schema validation happens after parsing, and the document fails well-formedness first.
Will it work on SVG, RSS or plist files?
Yes. All are XML underneath and use the same profile. There is also a dedicated SVG corrupter.
Can I keep it looking like valid XML?
Light level preserves most of the structure, so the file still looks like XML at a glance while failing to parse.
Is the file uploaded anywhere?
No. All processing happens in your browser and nothing is transmitted.