diffity

Diffity is a Mac app for reviewing code changes, yours or your agent's, GitHub-style, with Claude Code in the loop.

macOS 13.3 or later, Apple Silicon and Intel. The AI features need Claude Code (logged in) and Node.js.

What can you do?	Description
Comment on your diff	Leave comments on lines, files or the whole diff, then send them to Claude to fix
Let Claude fix your comments	Claude works through your comments, edits the code and replies in each thread
Ask @claude	Mention @claude in any thread and Claude replies right there
Get a Claude review	Claude reads the diff and leaves comments on the lines it cares about
Review any commit or range	Uncommitted changes, a commit, a range or a whole branch
Review pull requests	Check out a GitHub PR, review it locally, post the review back
Post reviews to GitHub	Submit as Comment, Approve or Request changes, with GitHub threads synced into the diff
Browse and comment on any file	Comment on code outside the diff from the Files tab
Jump anywhere	⌘P for files, ⌘K for commits, comments, PRs and every action
Switch projects	Keep your repos in a rail and switch with ⌘1–9
Open from the terminal or your agent	diffity opens a repo, a diff or a pull request URL in the app

Comment on your diff

Drag across line numbers or click the + in the gutter, write a comment, then hit Send to Claude to have it fix them.

Let Claude fix your comments

Hit Send N to Claude; it works through each comment, edits the code and replies in the thread, and you review its changes like any other diff.

Ask @claude

Type @claude in any comment or reply and Claude answers in the same thread.

Get a Claude review

Click Ask Claude to review, optionally add what to focus on, and its comments land on the diff as it works.

Review any commit or range

Open the picker next to the project name to switch between uncommitted changes, a commit, a range or a branch.

Review pull requests

Pick a PR from the branch switcher to check it out, comment as you read, then Submit review to post it to GitHub.

Post reviews to GitHub

Comment as you read, then Submit review as Comment, Approve or Request changes; GitHub comments sync back into the diff so you can reply or resolve from the app.

Browse and comment on any file

Open the Files tab, pick any file in the repo and comment on its lines, even code the diff doesn't touch.

Jump anywhere

Press ⌘P to open any file, or ⌘K to search commits, comments, PRs and every action.

Switch projects

Open a repo with ⌘O; it stays in the left rail, so ⌘1–⌘9 takes you back to it.

Open from the terminal or your agent

Run diffity in any repository to open it in the app, or pass a pull request URL to review it.

Install the command once from the app menu: Diffity → Install ‘diffity’ Command…. It links the command into /usr/local/bin and asks for your password if that folder needs it.

diffity                                        # uncommitted changes in the current repository
diffity ~/code/app                             # another repository
diffity --ref main                             # everything on this branch since it left main
diffity --ref HEAD~1..HEAD                     # the last commit
diffity https://github.com/owner/repo/pull/42  # check out and review a pull request
diffity src/app.ts                             # a file in the Files tab
diffity -n                                     # in a new window

--ref takes anything the ref picker does: work, staged, unstaged, a branch or commit, <a>..<b> or <a>...<b>. A pull request opens in the current repository if it is a clone of that repo, else in a clone Diffity already knows; with neither, Diffity offers to clone it. Run diffity --help for everything.

Coding agents can run it too, so you can ask Claude Code to “open your changes in Diffity” before it opens a PR.

More

• Find in the whole diff. ⌘F searches every file in the diff, including collapsed ones, and ⌘G jumps to the next match.

• Changed since you viewed it. Files you marked Viewed get a badge when they change again, and one click shows just what changed.

• Hide generated files. Add a .diffityignore to your repo (same syntax as .gitignore), or a list in Settings, and those files stay out of your diffs:

  dist/
  *.generated.ts
  !dist/keep-me.js

• Colour-blind friendly colours. Settings → General → Appearance switches the diff to blue and orange, in light and dark.

• Split or unified, light or dark. Toggle the diff layout anytime; the theme follows your Mac unless you pick one in Settings.

• Updates itself. New versions install in place, and What's New in the Help menu shows what changed.

Found a bug or have an idea? Open an issue.

License

MIT © Kamran Ahmed