What is PR understanding?

PR understanding is knowing what a pull request actually does, and why, well enough to approve it, at the speed the code arrives. DiffGuardian is built for it: it helps engineers, PMs and anyone building software understand a pull request by reading it as a walkthrough, hearing it spoken, or seeing what it touches.

#Why reading every line stops working

AI agents write code faster than anyone can read it. One agent can open a 5,000-line pull request before lunch, and several can work in parallel. That leaves two options: read everything, which does not scale, or approve without understanding, which does not hold up. PR understanding is the third option: get to the same grasp of the change in a fraction of the time.

#What it looks like

• A walkthrough, not a diff. The pull request is broken into the features it ships, each explained in plain English.
• The way in that suits you. Read it, hear it, or see it, whichever gets you there fastest.
• A decision you can defend. When you approve, you can say why the change is safe to ship.

#Three ways in with DiffGuardian

• Read it. Trace It (Pro) walks one feature at a time across every file it touches, at your own pace.
• Hear it. Talk to your pull request (Pro): ask out loud and hear the walkthrough while the code it explains is highlighted.
• See it. Blast radius graphs everything a change touches, from the diff alone.

The short version is in the docs: Understand a pull request quickly.

#Related guides

• How to understand a 5,000-line pull request without reading every line
• Keep up with coding agents working in parallel
• How to understand code written by AI agents
• A PM's guide to understanding AI-written code

DiffGuardian is a desktop app for macOS, Windows and Linux, and works with pull requests on GitHub, GitLab and Bitbucket.

#Limits

• Trace It and voice are Pro features. The blast radius graph works on every plan.
• You approve when you are ready. DiffGuardian never merges anything.