Patchtree — pretty diffs & code review

patchtree renders plain-text .diff / .patch pages as a fast, full-featured code-review interface — the kind you get on a merge/pull request, but on the raw diff itself, on any host.

Open a diff URL such as https://gitlab.example.com/group/project/-/merge_requests/104.diff (or click the toolbar icon on any MR/PR page) and review right there. It also renders local .diff / .patch files opened via file://.

Diff rendering

• Any plain-text .diff / .patch page, whatever served it — git-format or a plain diff -u, GitLab, GitHub, or a local file.
• Inline and side-by-side views; fully added or deleted files use the full width in split mode.
• Real syntax highlighting via tree-sitter (WebAssembly, run off the main thread): Go, JS/TS/TSX, Python, Bash, JSON, YAML, Rust, C, C++, Java, Ruby, PHP, C#, Lua, TOML, HCL/Terraform, CSS, HTML, and Helm/Go templates.
• Word-level diff: the exact words that changed get a stronger tint.
• Expand hidden lines between hunks, or a Full-file toggle per file.
• Large diffs stay smooth — only visible file sections are rendered.

• Resizable, filterable file tree (filter matches paths and diff content), status icons and colors (added / modified / renamed / deleted), per-file +N −M and comment-count badges.
• Filter by file extension; hide viewed or deleted files.
• Viewed checkboxes with an N/M progress counter; auto-collapse of generated files (lock files, vendored, minified, *.pb.go, …).
• Follows the file you're on and remembers your place across reloads.
• Keyboard: j/k files, n/p threads, v viewed, x fold, e toggle tree, / focus filter.
• Per-commit diff filter; copy-path, open-at-head, and line permalinks.

• Threads anchored to lines (old or new side), replies, edit and delete.
• Markdown editor with a toolbar and Write/Preview tabs, rendered through the platform's own API.
• Suggestions: one click prefills a suggestion block; existing suggestions render as a red/green widget with Apply (GitLab).
• Multiline comments (shift-click a line number to extend the range).
• Resolve / unresolve threads and an "unresolved" jump list (GitLab).
• Draft reviews and a Submit-review panel: Comment / Approve / Request changes, with the approval state shown as a badge.
• Pipeline/checks status and a merge-conflict indicator in the toolbar.

• Theme gallery with the base24 schemes from tinted-theming, live code previews (including how added/removed lines look), light/dark filter, and paste-your-own scheme YAML.
• Bundled fonts (JetBrains Mono, Inter, and Nerd Font builds), or any local font by name; separate UI/code font sizes, tab width, italic-comment and ligature toggles.

• Firefox MV3 treats host access as opt-in — enable Access your data for all websites (or grant specific hosts) in the add-on's Permissions tab, or the content script won't run.
• To render local files, allow the add-on access to file:// URLs.
• Rendering needs no account. To turn on review actions, open the ⚙ menu → Access tokens and add a GitLab host (PAT scope api) and/or a GitHub token (classic repo, or fine-grained with Pull requests read & write).

patchtree talks only to the diff's own host and its API (GitLab/GitHub) to render diffs and post your review actions. Access tokens are stored locally (storage.local) and never synced or sent anywhere else. No analytics, no tracking, no third-party servers.

Open source (Apache-2.0): github.com/danilrwx/patchtree