Have a look at File comparison tools, from which I am using WinMerge. It has an ability to compare XML documents (you may wish to enable DisplayXMLFiles prefilter for v2.14.0 or PrettifyXML for v2.16.x).

DisplayXMLFiles.dll - This plugin pretty-prints XML files nicely by inserting tabs and line breaks. This is useful for XML files that do not have line returns in convenient locations.

Note for v2.16.x

The plugin PrettifyXML is supplied with the software package. It can be activated as following:

  • Make sure that Plugins โ†’ Plugin Settings โ†’ Enable plugins is enabled.
  • Then use either File โ†’ Recompare As โ†’ Prettify XML or Plugins โ†’ Scripts โ†’ Prettify XML

For those who wish to play with deprecated DisplayXMLFiles, he needs to download e.g. winmerge-2.16.14-full-src.7z and copy Plugins\dlls\X64\DisplayXMLFiles.dll to WinMerge\MergePlugins\.

See also my feature comparison table.

Answer from dma_k on Stack Overflow
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Altova
altova.com โ€บ xmlspy-xml-editor โ€บ compare-xml
Compare XML Files | Altova
DiffDog also supports XML-aware comparisons, including graphical XML Schema differencing and will automatically generate an XSLT stylesheet to transform XML documents to the new XSD. You can download a free trial of DiffDog, or test drive the MissionKit tool suite, which includes both XMLSpy ...
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Xlcompare
xlcompare.com โ€บ compare-xml-files.html
Compare XML Files Online. Free. No Upload. Get the Semantic XML diffs.
October 3, 2009 - Compare two XML docs and get the difference online. Drop your files on this page and get the highlighted diffs. Get semantic XML differences by comparing XML documents with key nodes and attributes.
Discussions

Are there any free Xml Diff/Merge tools available? - Stack Overflow
Then use either File โ†’ Recompare ... Prettify XML ยท For those who wish to play with deprecated DisplayXMLFiles, he needs to download e.g. winmerge-2.16.14-full-src.7z and copy Plugins\dlls\X64\DisplayXMLFiles.dll to WinMerge\MergePlugins\. See also my feature comparison ... More on stackoverflow.com
๐ŸŒ stackoverflow.com
Comparing xml files
xmldiff https://pypi.org/project/xmldiff/ If you need a good visual diff, you can download a free oXygen trial maybe. That's the best visual tool I've used. More on reddit.com
๐ŸŒ r/xml
9
1
April 15, 2024
XML files comparison / diff?
Beyond compare software is perfect for this More on reddit.com
๐ŸŒ r/sysadmin
9
4
November 25, 2020
Good free .xml compare software?
Notepad++ can open XML and there's a compare add-on for that. All free. Google it. More on reddit.com
๐ŸŒ r/AskEngineers
4
5
February 11, 2020
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TextCompare
textcompare.org โ€บ xml
Online Xml Compare Tool
No Installation: This is a web based tool, no software installtion required. It works on any modern browser like Firefox, Chrome, Edge etc on Windows, Mac or Linux based computer. Unlimited: There is no limit on number of comparisons you can do. You can compare as many Xml files as you want. No, all the processing is done on your ๐Ÿ–ฅ browser, so nothing is saved on our server unless you choose to save to share online. For private sharing, you can download ...
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Ali-ulvi
ali-ulvi.github.io โ€บ XML_equality_checker_comparer.html
XML Compare Test Tool
Sometimes we need to compare XML files ignoring their elements' order but there was not such FREE tool before. Now there is! Download here.
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CoreFiling
corefiling.com โ€บ home โ€บ open source tools โ€บ xml comparison tool
Free Online XML Comparison Tool
June 20, 2025 - CoreFiling XML Differences uses XML Pretty Printer and a custom diff to display differences between XML files in an easy-to-read format. We hope you find this tool useful โ€“ please remember not to use online tools with production data!
Top answer
1 of 11
36

Have a look at File comparison tools, from which I am using WinMerge. It has an ability to compare XML documents (you may wish to enable DisplayXMLFiles prefilter for v2.14.0 or PrettifyXML for v2.16.x).

DisplayXMLFiles.dll - This plugin pretty-prints XML files nicely by inserting tabs and line breaks. This is useful for XML files that do not have line returns in convenient locations.

Note for v2.16.x

The plugin PrettifyXML is supplied with the software package. It can be activated as following:

  • Make sure that Plugins โ†’ Plugin Settings โ†’ Enable plugins is enabled.
  • Then use either File โ†’ Recompare As โ†’ Prettify XML or Plugins โ†’ Scripts โ†’ Prettify XML

For those who wish to play with deprecated DisplayXMLFiles, he needs to download e.g. winmerge-2.16.14-full-src.7z and copy Plugins\dlls\X64\DisplayXMLFiles.dll to WinMerge\MergePlugins\.

See also my feature comparison table.

2 of 11
22

I wrote and released a Windows application that specifically solves the problem of comparing and merging XML files.

Project: Merge can perform two and three way comparisons and merges of any XML file (where two of the files are considered to be independent revisions of a common base file). You can instruct it to identify elements within the input files by attribute values, or the content of child elements, among other things.

It is fully controllable via the command line and can also generate text reports containing the differences between the files.

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SemanticDiff
semanticdiff.com โ€บ online-diff โ€บ xml
SemanticDiff - Compare XML Online
Compare two XML files in your browser using our free semantic diff tool. See how values and attributes differ while ignoring formatting changes.
Find elsewhere
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Online Text Compare
onlinetextcompare.com โ€บ xml
Compare XML files online
FREE two-way XML format, diff and merge tool. No Signup required. Nothing to install. All comparisons are 100% private, secure and happens locally right in your web browser
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Oxygen XML
oxygenxml.com โ€บ xml_diff_and_merge.html
Oxygen Compare and Merge Tools
The complete XML diff and merge ... and XML fragment comparisons, six different algorithms, and multiple levels of comparison. In large teams composed either of developers or technical writers, the use of a shared repository is essential. It is common for numerous authors to be working on the same file simultaneously. In this case, finding what has been modified in your files and folders can often be difficult. To help you with this, Oxygen includes diff tools for comparing ...
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Minifier
minifier.org โ€บ xml-compare
XML Compare - Online XML Diff Checker
No need for downloads or installations. Use the XML comparison tool directly in your browser for quick and secure XML comparison.
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Altova
altova.com โ€บ diffdog
DiffDog Diff/Merge Tool | Altova
As MusicXML became more popular, ... testing tool that we had long sought for our MusicXML projects.โ€ ... Download a free 30 day trial of Altova DiffDog now!...
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LambdaTest
lambdatest.com โ€บ home โ€บ free tools โ€บ xml compare
XML Compare - XML Diff Online Tool | LambdaTest
Free and Accessible: Our XML Compare Tool is free to use and doesnโ€™t require any downloads or installations, making it accessible from any device with an internet connection.
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Stylus Studio
stylusstudio.com โ€บ xml-diff.html
XML Diff Tool
The bottom right of this illustration shows Stylus Studioยฎ's Directory differencing tool that allows you to compare entire directories. The XML Diff tool is integrated with the XML Tree View and the XML Text View of Stylus Studioยฎ's XML Editor, and switching views is just a matter of choosing ...
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GitHub
github.com โ€บ vkononov โ€บ compare-xml
GitHub - vkononov/compare-xml: CompareXML is a fast, lightweight and feature-rich tool that will solve your XML/HTML comparison or diffing needs. its purpose is to compare two instances of Nokogiri::XML::Node or Nokogiri::XML::NodeSet for equality or equivalency.
August 30, 2018 - CompareXML is a fast, lightweight and feature-rich tool that will solve your XML/HTML comparison or diffing needs. its purpose is to compare two instances of Nokogiri::XML::Node or Nokogiri::XML::NodeSet for equality or equivalency.
Starred by 13 users
Forked by 3 users
Languages ย  Ruby 58.1% | HTML 41.6% | Shell 0.3% | Ruby 58.1% | HTML 41.6% | Shell 0.3%
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DeltaXML
deltaxml.com โ€บ home โ€บ products โ€บ compare โ€บ xml compare
Compare 2 XML Documents with Ease Using XML Compare
October 2, 2024 - Reliable XML comparison tool. Find the difference between two XML files and represent the change. Works with all XML. Works with large files.
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JSoftwareLabs
jsoftwarelabs.com โ€บ compare-diff-online โ€บ xml-comparison
Compare xml online - XML diff tool
JSoftwareLabs' free XML comparator tool allows you to compare XML nodes visualize the semantic differences. Paste your XML code,compare the code side-by-side and see a detailed table with change locations.
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GitHub
github.com โ€บ Shoobx โ€บ xmldiff
GitHub - Shoobx/xmldiff: A library and command line utility for diffing xml
A library and command line utility for diffing xml - Shoobx/xmldiff
Starred by 226 users
Forked by 53 users
Languages ย  Python 98.7% | Python 98.7%
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ExtendsClass
extendsclass.com โ€บ xml-diff.html
XML diff - Compare xml online
There are several free online tools that can help you with this, such as Flexter XML to SQL online. ... You can report a bug or give feedback by adding a comment (below) or by clicking "Contact me" link (at the top right hand corner of the page). Comments ...
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Liquid Technologies
liquid-technologies.com โ€บ compare-xml-files
Compare XML Files
The Liquid Data Diff Viewer has an XML specific differencing tool, enabling users to quickly compare two XML files.