The Best Diff Tools

Who this is for

A diff tool shows you exactly what changed between two versions of something: two drafts of a contract, two config files, two folders of photos, or your branch and a colleague’s. Changed words are highlighted, and lines that were added or removed are marked, so you don’t have to read both versions line by line.

If you only compare a couple of snippets of text now and then, a free website is enough. If you compare whole folders, review code, or resolve merge conflicts, it’s worth installing a desktop tool and connecting it to Git. Most developers already have something that works. This guide is for deciding whether something better is worth the setup or the money.

Why you should trust us

We build DiffCheck.io, an online diff checker, so we spend a lot of time on how a diff should be laid out and where diffs tend to mislead. That is also a conflict of interest, because DiffCheck.io appears in this guide. We’ve kept it out of the main picks, and we’re plain about what it can’t do.

For this guide we went through each tool’s documentation, feature list, pricing page and release notes as they stood in October 2026. We didn’t run our own benchmarks, and we don’t claim to have. Where a feature depends on a paid edition, a plugin or a community build, the feature table below says so.

How we picked

A good diff tool should:

• Highlight changes inside a line, not only which lines changed. If one word in a long paragraph changes, you should see the word.
• Compare folders as well as files, so you can see what changed across a whole project.
• Offer a three-way merge view, which is what you need when Git reports a conflict.
• Work with Git as a difftool or mergetool.
• Run on your platform and still be maintained.
• Be free, or be clearly better than the free options.

We started from the tools that come up most often in developer discussions and comparison lists, and narrowed them down against those points.

Beyond Compare, made by Scooter Software, compares text files, folders, spreadsheets, images and binary files. Version 5 runs on Windows, macOS and Linux and costs $35 for the Standard edition or $70 for Pro. That is a one-time price: minor updates are free, and major upgrades have usually been sold at half price.

Folder comparison is where it pulls ahead. Point it at two directories and it lists every file side by side, marked as the same, different, or present on only one side. You can hide everything that matches, open any pair of files in a text comparison, and copy files across to bring the two folders back in line. It can compare files by size and date for speed, or by their contents when you need to be sure.

The text view highlights changes within each line, and you can tell it to ignore differences that don’t matter, such as whitespace or line endings. Both editions can be set as Git’s diff tool. Pro adds a three-way merge view for resolving conflicts.

Flaws but not dealbreakers

The interface is busy. There are a lot of toolbar buttons and session settings, and it takes time to learn where things are. Three-way merge is only in Pro, so developers should plan on the $70 edition. And this is paid software in a category with good free options. If you mostly compare text, WinMerge or Meld will do. A 30-day trial is free, which is long enough to find out whether the folder tools are worth it to you.

WinMerge has been around for more than twenty years. It compares files and folders, supports three-way comparison and merging, and can compare images. It adds itself to the File Explorer right-click menu, so you can select two files and compare them without opening the app first.

Plugins extend it to other formats. Some unpack archives so their contents can be compared, and others extract the text from documents. Git supports it by name as a diff and merge tool.

Flaws but not dealbreakers

It only runs on Windows. Its folder comparison is good for finding and copying differences, but Beyond Compare has more options for keeping two folders in sync.

Meld is a GNOME project. It shows two or three files side by side and joins the matching sections with curved bands, which makes it easy to follow a block of text that moved or grew. Arrows in the margin copy a change from one side to the other.

It also compares folders, and it has a version-control view for Git, Mercurial and Subversion that lists your changed files and opens each one as a diff. Git supports it by name, so setting it up takes two commands (see setting up a diff tool with Git).

Flaws but not dealbreakers

Meld is built for Linux first. There’s an official Windows installer, but the Mac version is maintained by volunteers outside the main project and installed through Homebrew. It works, but it can lag behind the Linux release.

Kaleidoscope compares text, images and folders in a native Mac app with a clean, uncluttered layout. Image comparison is a particular strength. It connects to Git through its ksdiff command-line tool, so you can review changes and resolve merge conflicts in the app.

Flaws but not dealbreakers

It’s Mac only, and since version 4 it has been sold as a subscription. Beyond Compare also runs on the Mac and costs less over time, so Kaleidoscope is for people who care enough about the experience to keep paying. There’s a free trial.

Also great

For merge conflicts: KDiff3

KDiff3 is free and runs on Windows, macOS and Linux. In a three-way merge it shows the common ancestor and both changed versions above an output pane, merges everything that doesn’t conflict, and leaves only the real conflicts for you to choose between. It looks dated, but for merges it’s one of the best free options. apps.kde.org

For developers: VS Code, delta and difftastic

If you write code in VS Code, you already have a capable diff tool. Select two files in the Explorer and choose Compare Selected, or run code --diff old.txt new.txt in a terminal. Git conflicts open in its three-way merge editor. code.visualstudio.com

In the terminal, delta improves the output of git diff, git log and git show with syntax highlighting, word-level changes and an optional side-by-side layout. difftastic compares code by its syntax, so reformatting doesn’t show up as a change. Both are free and open source. github.com

For quick comparisons online: DiffCheck.io

This is our tool, so weigh this paragraph accordingly. DiffCheck.io runs in the browser: paste two pieces of text or upload two files and the differences are highlighted side by side. It reads PDF, Word and Excel files, has a JSON mode that ignores key order, and can compare two lists. It’s free, needs no account, and the comparison runs on your own computer. It doesn’t compare folders or handle merges, which is why it isn’t higher in this guide. Open DiffCheck.io

The competition

Diffchecker is the best-known online diff site. The free web version compares text, images, PDFs and spreadsheets. Its desktop app comes with the Pro + Desktop plan at $15 per user per month, which adds up to more in a year than a Beyond Compare licence costs once.

P4Merge, from Perforce, is free and popular with Git users for its clear three-way merge view. It doesn’t compare folders and has changed little in recent years, so KDiff3 gets our recommendation for merges instead.

Araxis Merge is a capable commercial tool for Windows and macOS that can also compare Office documents and PDFs. It costs $129, or $269 for the Professional edition with three-way merge. That’s a lot more than Beyond Compare for a similar set of features.

Setting up a diff tool with Git

Git can open diffs and merge conflicts in an external tool. These are the commands for the tools above.

git config --global diff.tool meld
git config --global merge.tool meld

git config --global core.pager delta
git config --global interactive.diffFilter 'delta --color-only'
git config --global delta.navigate true
git config --global merge.conflictStyle zdiff3

GIT_EXTERNAL_DIFF=difft git diff

Prices and features were checked on October 17, 2026. Spotted something out of date? Tell us.