Show HN: Codiff, a local diff review tool
Nowadays I review a lot of code locally that was written by llms. I used to review my own code using git + delta. It started to feel limiting with the amount of code written by llms. When looking at a large diff on Friday I pointed an llm at diffs.com and trees.software and told it to build an app. It only took 16 minutes, is extremely fast for large diffs, beautiful and minimal. Today I polished it up and added all the features that I need. It has file filters, search, an llm walkthrough mode, and review comments that you can paste back into your llm. I will be using Codiff a lot, and can finally review the large diff from Friday that led me to build this If you like it, fork it!
Discussion Highlights (7 comments)
sjhalani7
That's awesome. Been reviewing code diffs on the IDE and it's been hard, so will check this out!
atmanactive
... for MacOS.
usernametaken29
Surprisingly enough this has just a few features the JetBrains diff view is lacking, notably file search… good ideas
realrocker
:) We are all converging on the same problems and tooling to fix them. Built this in the last couple days to review changes done by claude on a hetzner box(over tailscale on my phone) and leave comments before pushing to remote : https://github.com/livetemplate/prereview . Runs everywhere and can has a claude skill: /prereview which starts a new instance for the current changes. Has a “Hand-off” button to signal claude to process the comments. UI is responsive. I use it on my iphone with claude mobile app + /remote-control to leave comments before pushing.Still requires polish but core features work.
stephenr
Who knew that the killer task for LLMs would be "recreate existing things that exist without me mentioning them by name, based on a worse alternative as the example". Kaleidoscope exists. File Merge exists.
tcoff91
Can you include screenshots in your readme? Also does it only work for staging and unstaged changes? I use jj so I need to be able to point it at commits since jj has no staging it just creates a new git commit snapshot every time you run any jj command.
magnio
Is diff viewer the 2026 todo list? List of vibe coded alternatives: - revdiff: https://github.com/umputun/revdiff - hunk: https://github.com/modem-dev/hunk - diffnav: https://github.com/dlvhdr/diffnav - diffx: https://github.com/wong2/diffx - lumen: https://github.com/jnsahaj/lumen