Are there any free Xml Diff/Merge tools available? [closed]

S

11

110

I have several config files in my .net applications which I would like to merge application settings elements etc.

I was about to begin doing it manually as I usually do, however thought there must be an XML diff GUI tool available somewhere.

The tool would be able to go to the element level to compare and display the differences etc.

However Google gave no substantive free tool results and no hints for anything of value.

Is such a tool available? That is very useful? For free?

Thanks in advance. :)

Edit:

Here is a bit of clarification of the functionality that would turn my error-prone, tedious manual job into a 1-minute simpler task (and potential to automate):

In KDiff3, you can do a diff/merge of entire directories. There is a hierarchical diff which is very accurate, user-friendly and clear. I was interested in finding a similar solution, however instead of directory hierarchy, an XML element hierarchy.

If there is no such open source software, I am considering creating one on CodePlex to provide this functionality.

Swiss answered 9/12, 2009 at 1:28 Comment(3)

I recently came across this website which does some xml and json comparison online. jsoftwarelabs.com/jslutils/xml-comparison – Demott 25/2, 2022 at 12:25

jsoftwarelabs.com/jslutils/xml-comparison – Demott 25/2, 2022 at 12:26

@Demott that one works just great. Had to compare two files with lists of different order and could easily verify if all elements where present even when in random order. – Kindhearted 9/3, 2022 at 14:15

L

10

KDiff3 is not XML specific, but it is free. It does a nice job of comparing and merging text files.

Laciniate answered 9/12, 2009 at 1:31 Comment(13)

I agree I am using KDiff3 at the moment, however a tool specifically for XML that could go down to the element level would be terrific. – Swiss 9/12, 2009 at 1:32

If a child of a node has changed, then surely the node itself has materially changed. I don't think I quite follow what a tool specific to XML would do in such a case that would be different from diff (pardon the pun). – Peary 9/12, 2009 at 1:35

I was thinking from this perspective: the way KDiff does a hierarchical diff of directories, a hierarchical diff of elements could also work. So if an element has changed, then I agree, the parent elements should also be flagged as having changed. – Swiss 9/12, 2009 at 1:38

Ah, I get it now, many thanks. You're looking for a diff tool that can report a change in a line of text that actually hasn't itself changed, but for which a "nested" line of text has changed. Gotcha. That would be very useful. Apologies for not cottoning-on earlier. – Peary 9/12, 2009 at 1:48

everyone realizes that in xml the child nodes are not guaranteed to be in any specific order, so any "tool" that reported that something was not in the same order from one file to the next really won't be a real xml compliant tool – Generalissimo 9/12, 2009 at 2:47

Yeah that makes this more complicated, however there may be ways to help the diff tool, eg. attributes may indicate which elements are the same in the two documents etc. Good point though :) – Swiss 9/12, 2009 at 2:52

Even assuming we could control the order by ordering alphabetically first would eliminate any issues with XML element order. – Swiss 8/2, 2011 at 0:24

If the order changes, then the elements are different. Depending on the semantics of the XML document in question, the order may, or may not, be significant. E.g. in XHTML obviously the order matters. – Cachet 30/10, 2013 at 14:56

The point is that a regular diff tool works line based. There are specific diff tools for e.g. CSV files that understand the format it is diffing. The better that understanding, the more effective the diffing can happen. A good XML diff tool would be able to parse the XML, use a schema to determine constraints such as whether order matters for example, and then use that knowledge to give a far more effective diff / merge experience. – Hoeg 11/7, 2017 at 8:35

@JarrodRoberson I don't get your argument. A XML diff tool is used to visualize changes in the file, it's not used to validate it in any way. Order can obviously be very significant for many consumers of XML. – Underproduction 15/11, 2017 at 16:1

@Underproduction - order is not guaranteed by the XML specification and any specific parser implementation could change from version to version so the order in the text file is irrelevant to the order in the parsed result. – Generalissimo 15/11, 2017 at 17:7

@JarrodRoberson You are being unnecessary general. A specific parser could very well guarantee order. And XML schemas are perfectly fine with defining order. Your argument that a xml-specialiced diff tool that shows differing order wouldn't be xml compliant is just strange. Again, it's a diff tool, not a validation tool. The purpose of a diff tool is to show changes between versions, of course it should show when you are moving things around. And the order might very well be the difference of the file being valid or not accordingly to a specific XML scheme. – Underproduction 15/11, 2017 at 22:5

elements and attributes in different orders is different, there is no arguing that saying that they can be in different orders and be the same is ignoring that fact. – Generalissimo 16/11, 2017 at 15:42

S

34

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 → Plugin Settings → Enable plugins is enabled.
Then use either File → Recompare As → Prettify XML or Plugins → Scripts → 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\.

WinMerge in action

See also my feature comparison table.

Sensitivity answered 23/8, 2011 at 13:29 Comment(6)

+1 Winmerge version 2.12.4.0; Menu "Plugin" -> "List" -> check "Enable Plugins"; Menu "Plugin" -> check "Automatic unpacking". Tested with XML file with file name with extension .xml and it seems to work. – Demiurge 14/9, 2011 at 9:43

It doesn't deal well with attributes being in different orders, so it's usefulness might be limited, depending on your situation. – Buford 8/3, 2012 at 20:50

Use this transform on any XML files first to sort elements and attributes: https://mcmap.net/q/196502/-xslt-to-sort-nodes-by-name – Juggler 8/4, 2014 at 11:34

Looks like the plugin is no longer available. – Allineallis 23/5, 2017 at 20:53

I'm not sure why it's not in the installer, but I was able to get it from their src repo on bitbucket / source code (sourceforge DL) : bitbucket.org/winmerge/winmerge/src/… – Cuirassier 8/4, 2019 at 21:18

There is an item in the menu: "File > Recompare As > XML" Version 2.16.8.0 – Evocator 5/8, 2021 at 7:18

D

21

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.

Project: Merge merging three XML files

Dustindustman answered 27/2, 2011 at 20:45 Comment(4)

I've tried Project::Merge and unfortunately it was not able to cope with my task. I have HTML text in paras (<p>) which is added formatting (like <i>, <em>). So Project::Merge shows that complete para was changed, it does not do in-depth word analysis. – Sensitivity 23/8, 2011 at 9:28

Yes, I'm sorry to say that XHTML (it will never do legacy HTML) support is pretty limited in that respect, as is text differencing within XML blocks in general. Most work so far have been focused on configuration-style XML files where free form character data is limited in its extent and usage. Hopefully I'll improve Project: Merge in this area in a future release. – Dustindustman 25/8, 2011 at 17:5

-1, The OP asked about free software. Project Merge is trialware and also hasnt been updated in 3 years. – Romanesque 2/7, 2014 at 14:20

Project:Merge has now been replaced by Oso XML Merge: osocorporation.com/xmlmerge/index.php – Thersathersites 4/8, 2016 at 23:48

G

14

There are a few Java-based XML diff and merge tools listed here:

Open Source XML Diff written in Java

Added links:

Godding answered 9/12, 2009 at 1:35 Comment(3)

I am having trouble finding any links to the software in the link you mentioned. – Swiss 9/12, 2009 at 1:42

Yeah, me too! Might need to Google around a bit... – Godding 9/12, 2009 at 1:58

Not useful without listing the tools' XML-specific capabilities. From what I can see, these are all regular diff tools without element-level comparison. – Arvind 18/9, 2023 at 7:59