Branch Diff: compare working directory against a selected target branch

[jdutheil]

What are you proposing?

A branch diff view that shows all changes (committed + uncommitted) between the current working directory and a user-selected target branch, fully integrated into the Git Panel.

Key capabilities:

1. Branch picker -- when triggering the "Branch Diff" action, a fuzzy-searchable picker lets you select the target branch (local or remote), instead of being hardcoded to the default branch.
2. Git Panel integration -- the Changes panel shows the changed files in a tree view (like the project file tree), with click-to-navigate to each file in the diff editor.
3. "Viewed" checkbox -- each file gets a checkbox (both in the panel and inline in the diff editor's file headers) to mark it as reviewed. Checking it auto-collapses the file.
4. Toolbar -- shows the target branch name (e.g., "vs feature/parent-branch") with a dropdown to change the target without closing the view.
5. Persistent panel -- the file list stays visible when switching tabs, clearing only when the diff tab is closed.
6. Staging controls and commit editor are hidden since this is a read-only comparison.

Why does this matter?

No way to review committed changes

Today, the Git Panel only shows uncommitted changes (staged/unstaged vs HEAD). Once changes are committed, they disappear from the panel entirely. There is no way to see the full picture of what a branch has changed. The existing "View Branch Diff" button is very limited: it only appears when there are zero uncommitted changes, it's hardcoded to the default branch, and the diff opens without any file list in the panel.

AI-assisted development workflow

This is becoming a critical gap for AI-assisted workflows. When working with Claude Code (or similar tools), a common workflow is:

• Ask the AI to implement changes and commit atomically
• Review section by section, validating each batch of changes before moving on
• Iterate until the feature is complete

Today this is impossible in Zed: once the AI commits, the changes vanish from the Changes panel. There's no way to see the accumulating branch diff, track which files have been reviewed, or navigate the changes. You end up having to use external tools (GitHub PR preview, git diff in terminal) to review what your AI just wrote -- defeating the purpose of an integrated editor.

Stacked branches

With stacked branches / stacked PRs, you need to diff against the parent branch, not main. If I'm on Approval-Tab which extends Applies-To, I need to see only the delta between these two -- not everything since main.

What problem does this solve?

Every Git GUI and code review tool (GitHub, GitLab, VS Code GitLens, IntelliJ) lets you choose a base branch for comparison and browse changed files. Zed currently has no equivalent. This feature turns Zed into a capable local code review tool, covering:

• AI-assisted workflows -- reviewing and validating AI-generated commits incrementally, with progress tracking
• Pre-push review -- seeing the full branch diff (committed + uncommitted) before pushing
• Stacked branches / stacked PRs -- diffing against the actual parent branch
• Self-review -- understanding what a branch actually changed, including already-committed work

Working prototype

I have a working local implementation of this feature (~700 lines across 3 files). I'd be happy to clean it up and open a PR if there's interest.

Files modified:

• crates/git_ui/src/project_diff.rs -- Branch picker, diff base selection, inline viewed checkbox
• crates/git_ui/src/git_panel.rs -- Git Panel integration, tree view, viewed state tracking
• crates/project/src/git_store/branch_diff.rs -- merged_file_list() accessor, set_diff_base(), tree_diff() accessor

Screenshots:

[lionel-]

This is sorely needed when working with stacked PRs.

Note that github is working on adding better support for this: https://github.github.com/gh-stack/

[jdutheil]

Yes I saw the Github work, but the whole idea is to be able not to leave the IDE, and to work locally
Also, right now I'm working with Gitlab in my company, so basically not possible with Github :D

[lionel-]

oh I'm mentioning this because I think it reinforces the need for stacked PR support in Zed.

[ctxx3]

This is exactly what I currently need! I hope you'll manage to add this feature

[yshen-notion]

Really want this

[malcolmgreaves]

+1 for this feature. It's frustrating to not be able to use Zed's awesome diff view except for an extremely narrow use case.

[lurodrigo]

Came here from google searching precisely how to do that in Zed. +1, hope it's implemented soon

[IWANABETHATGUY]

We should open issue rather than discussion, top ranking issue will be picked up with higer priority. #5393

[lionel-]

An issue was opened yesterday: #55650

[jdutheil]

According to the contribution guidelines, we're supposed to open discussions rather than issues for new features. The linked issue is likely to get closed :(

[awgn]

I think someone will have to give this serious consideration. I don't imagine anyone would object to a feature like this—which, in my opinion, should have been integrated into Zed the very day they released the Git interface. +1; there are people who desperately need this (myself included).

[AnkanMisra]

the picker is mostly a constructor-immutability thing. BranchDiff::diff_base has a getter but no setter (branch_diff.rs:109), and new_with_default_branch hardcodes repo.default_branch(true) (project_diff.rs:304). add a setter, swap the hardcoded call for a picker, drop the changes_count == 0 && !is_on_main_branch gate at git_panel.rs:4835 and that alone closes #55650.

probably worth landing that first before the panel/tree/viewed work. marked_entries already exists on GitPanel with a TODO (git_panel.rs:5585) so the viewed checkbox is less new than it looks.

[erik9631]

Need this too. There already seems to be a diffing tool for commits in the Graph viewer, but I have to go by commits.

[JosephTLyons]

Choosing a base branch in the branch diff view has shipped in Zed Stable v1.4.2!

[jdutheil]

That's good, but we're still missing a proper tree view for the files (any view in fact, the git panel is completely empty)