Claude Code Now Shows You the Diff While It's Still Editing

I used to run two terminal panes for every real Claude Code session: one with Claude, one sitting on git diff so I could actually see what it had touched. That was true whether I was watching it refactor my own code or reviewing what it did in someone else's repo during a call. Claude tells you what it changed in plain English at the end of a turn, and plain English is exactly the layer where a quiet scope change hides. "Updated the pricing logic" can mean one conditional or four files.

On September 3, that second pane stopped being necessary. Claude Code shipped a diff panel that sits right beside the conversation and updates live while Claude is still working, not after.

What actually shipped

Per the official changelog, Claude Code v2.1.260 added a diff panel that opens beside the conversation in fullscreen mode and shows your uncommitted changes as Claude edits, toggled with /diff. The docs page for it fills in the part the changelog line doesn't: /diff has actually existed for a while, but it used to open a full-screen viewer that took over your prompt until you closed it. Read a diff, press Escape, go back to typing. That's still what happens in the classic renderer.

In fullscreen rendering (the flicker-free terminal mode most people have been defaulted into since May, whether they noticed or not), /diff now opens a panel instead of a takeover. It stays open. You keep typing, keep reading Claude's replies, and the panel just sits there refreshing every time a file gets edited or a shell command runs something. You watch the diff accumulate in real time instead of requesting a snapshot of it after the fact.

That's the whole shape of it: your usual conversation on the left, a running ledger of every file Claude has touched on the right, with add and remove counts per file and the actual diff underneath. Test files and generated files get collapsed into one line at the bottom by default, since those are rarely what you're checking. Click the line and they expand.

The part almost nobody will find on their own: Ctrl+X B

The panel doesn't just show one diff. Press Ctrl+X B and it cycles through three different comparisons, and Claude Code remembers which one you picked per project:

1. This session's changes - just what's happened since you opened Claude Code, useful when you're mid-conversation and want to know what this specific run of work has done
2. All uncommitted changes - the standard git diff, everything sitting in your working tree regardless of when it landed
3. Everything since your branch split from main - the full scope of the branch, including anything you already committed

That distinction matters more than it looks. If you're three hours into a long session and Claude has been going back and forth across a dozen files, "this session's changes" is the only view that tells you what today actually did, separate from whatever you'd already committed before you sat down. Without the toggle you're stuck reading the branch-wide diff and mentally subtracting your own earlier commits.

The panel also lets you select lines directly with the mouse and attach them to your next prompt, so "explain why you did this" or "actually, revert just this part" can point at an exact block instead of you describing it in words. That's a small thing on paper and a real one in practice, because pointing beats describing every time.

Who this actually changes things for

If you've been running Claude Code for a while and you already had git diff open in a second pane out of habit, the panel mostly saves you the pane. Genuinely useful, not life-changing.

The bigger shift is for the operators and builders in Claude Camp who don't come from an engineering background and never had that second pane in the first place. Before this, the honest answer to "how do I know what it actually changed" was "read its summary and trust it, or learn git diff." Now the panel is just there, visible the whole time, updating as it goes. You don't need to know git to watch three files light up with new lines while Claude works and ask it about the one line that looks off. That's the actual gap this closes: not speed, visibility for people who never had a way to check.

Turning it on

Three requirements, straight from the docs: you need fullscreen rendering, a real git repository, and a terminal at least 110 columns wide. Run /tui with no argument to check which renderer you're currently in. If it says classic, /tui fullscreen switches you over without losing your conversation. Then /diff opens the panel. Widen your terminal to 144 columns and it'll start opening on its own the moment Claude edits a file, no command needed. Close it once and it stays closed until you ask for it again, in that session and future ones.

The rest of that release week, briefly

Two more things shipped the same week worth knowing even though they weren't the point of this post. /skill-doctor (v2.1.261, September 4) lists which of your loaded Skills are actually being used and what they're costing you in context, so you can prune the ones quietly eating tokens for nothing. And bashOutputMaxChars / taskOutputMaxChars, same release, raise how much command and background-task output Claude receives inline before it gets saved to a file instead, up to 128K characters. If you've ever had a build log or a test run get truncated mid-review, that's the setting that fixes it.

None of that changes the headline here. The diff panel is the one I'd tell someone to go turn on today, because it replaces trust with something you can just look at.

If you want the rest of the operator stack around Claude Code, not just the individual features as they ship, that's what the 2-day Intensive is for. Live, hands-on, one real project built start to finish.