Viewing diffs

The diff viewer shows the changes of one file: in your working tree, in the index, in a commit, in a stash or between two compared revisions. This page covers how to open and read it, its options and keyboard navigation, and the special cases (binary files, images, Markdown, large files). Staging hunks and lines from the diff is covered in Staging changes.

Open and close a diff

Click a file in any file list to open its diff in place of the graph; the right panel stays as it is. File lists appear in:

• The Unstaged and Staged lists of the changes panel.
• The commit details panel, when a commit is selected (see The commit graph). A merge commit is compared with its first parent.
• The Stash details panel (see Stash).
• The Changes tab of a comparison.
• The file history.

To go back to the graph, click Graph at the left of the diff toolbar, press Esc, or click the open file again in its list. In a working-tree diff with selected lines, the first Esc clears the selection and the second closes the diff. A working-tree diff closes by itself when its file leaves the list (for example, once staged or discarded).

The diff toolbar

From left to right:

Element	Description
Graph	Back to the graph (Esc)
Status letter	Same letters and colors as in the file lists
Path	The file path, old → new for a rename
Line counts	+added −removed
Position	{index} / {total} in the file list (hidden when the diff area is narrower than 760 px)
Previous file / Next file	Move in the file list (K / J); disabled at either end
Edit	Edit the file in place (unstaged diffs only, see Edit a file in the diff)
Open outside yaggui	Menu: diff tool, editor, file manager
File history, Blame	Open the file history or blame of the file (Blame at this commit for a commit diff)
Diff layout	Unified, Side by side, plus Preview for Markdown files
Diff options	The options menu (gear icon)

Unified or side by side

Side by side (the default) shows the old version on the left and the new one on the right, scrolled together. Unified shows both in one column. Switch with the Diff layout control or ⌘D (Ctrl+D on Windows and Linux). The choice is saved and applies to every repository. ⌘D is fixed and cannot be rebound.

Diff options

The Diff options menu holds:

Option	Default	Effect
Wrap lines	Off	Wraps long lines instead of scrolling horizontally. Side-by-side rows stay aligned
Ignore whitespace	Off	Hides whitespace-only changes, like git diff -w, including line-ending changes. Disables hunk and line staging while on
Show the whole file	Off	Shows the whole file as one hunk
Context lines	3 lines	Unchanged lines around each change: 0, 3, 10 or 25

These options are saved and apply to every diff in every repository. They are not in the Preferences dialog; see Preferences for where they are stored.

If Ignore whitespace hides everything that changed, the diff says Only whitespace changed or Only the line endings changed and offers Show whitespace changes, which turns the option off.

Read the diff

• Syntax highlighting follows the file name’s language and appears a moment after the diff.
• Changed words are highlighted inside modified lines. Very long lines, and lines that changed almost entirely, are shown as wholly changed.
• Hunk headers show @@ -a,b +c,d @@ followed by the nearest enclosing function or section line.
• No newline at end of file is marked when a file’s last line has no line break.

yaggui computes diffs itself (no git diff process). It honors diff.algorithm and the binary and -diff attributes of .gitattributes, but does not run external diff drivers (diff.<driver>.command) or text conversions (textconv).

Navigate with the keyboard

These keys work when focus is not in a text field:

Key	Action
N / P	Next / previous change. Each run of changed lines is a stop; the current one is highlighted
J / K	Next / previous file of the same list (in file history: older / newer commit)
⌘D (Ctrl+D on Windows and Linux)	Toggle unified and side by side
Esc	Clear the line selection, otherwise back to the graph
↑ / ↓	In the file list: previous / next file. In a working-tree diff: move the line cursor (see Staging changes)

All shortcuts are listed in Keyboard shortcuts.

Notices

A notice bar above the code reports changes that are not visible as lines:

Notice	Meaning
Renamed from {from} ({similarity}% similar)	Rename or copy detected; similarity is 100% for an identical file
File mode changed: 100644 → 100755	The executable bit (or another mode) changed
Line endings changed: LF → CRLF. Ignore whitespace to hide these lines.	Every line changed only by its ending; CRLF + LF means mixed endings
Mixed line endings (CRLF and LF)	The new version mixes both endings
Not UTF-8: shown as Windows-1252 (guessed encoding)	The file is not valid UTF-8

Renames and copies are detected like git diff -M -C. Without any content change, a mode-only change says Only the file mode changed.

Some files show a placeholder instead of code:

• Submodule commit changed: the old and new commit of a submodule.
• File stored with Git LFS: “Only a pointer is versioned: no text diff.”, with sizes and object ids (see Git LFS).
• Merge conflict: resolve it in the conflict editor (see Conflicts).
• No content change.

Large files

To stay fast, yaggui does not render diffs over 5,000 lines or files over 1 MB. It shows Large diff not shown with the line count (“This diff has {lines} lines. Showing it may slow yaggui down.”) or the size (“This file weighs {size}. It was not loaded, to keep yaggui fast.”). Click Show anyway to render it; yaggui remembers this for that file until you quit.

Binary files

A binary file that is not an image shows Binary file with its size Before and After (a dash for a missing side).

Images

PNG, JPEG, GIF, WebP, BMP, ICO, SVG and AVIF files are shown as pictures, titled Image changed, Image added or Image deleted, with each side’s dimensions and size in the Side by side mode. When both versions exist, Image comparison offers:

Mode	Use
Side by side (default)	Both versions next to each other
Onion skin	The new version over the old one; the Opacity of the new version slider fades between them
Swipe	One image split by a divider; the Position of the divider slider moves it

The mode stays selected for other images until you quit. Images over 8 MB are not previewed (“This image is too large to preview (8 MB at most).”). For an SVG, Show the SVG source switches to a text diff, and Show as image in the toolbar switches back. SVGs are displayed as images, so their scripts never run.

Markdown preview

For Markdown files (.md, .markdown, .mdx and similar), the Diff layout control has a third choice, Preview. It renders the new version of the document and marks the changes:

• Changed, added and removed blocks are marked in the margin; inserted words are highlighted and removed words struck through in place.
• A strip counts {count} blocks added, removed and changed. N and P, or Next change and Previous change, move between changes (Change {index} / {total}).
• Show removed text (on by default) hides or shows removed text.
• Renumbering an ordered list is not counted as a change. If only spaces or line breaks changed: “No change in the rendered text (spaces or line breaks only)”.

The preview is a saved setting for all Markdown files; choosing Unified or Side by side, or pressing ⌘D, leaves it. Raw HTML is shown as code, links do not navigate, and images are shown as their alt text. A very large document says “This document is too large to be rendered.” with Render anyway.

Edit a file in the diff

In an unstaged diff of a text file, Edit turns the diff into an editor of the working-tree file, with the lines that differ from the index marked.

1. Make your changes. The toolbar shows Unsaved changes.
2. Click Save or press ⌘S (Ctrl+S on Windows and Linux). The toolbar shows Saved.
3. Click Done to go back to the diff. With unsaved changes, Discard your changes? asks first.

If you leave the file without saving, your edits are kept until you quit and come back when you reopen it. If the file changes on disk while you have unsaved edits, yaggui says “{path} changed on disk while you were editing it.” and offers Reload from disk or Keep my version.

Editing is not offered for staged or commit diffs, and is refused for LFS files, files over 1 MB, non-UTF-8 or binary files and files mixing LF and CRLF endings (“This file cannot be edited”).

Caution

Saving writes the file directly. It is not recorded in the undo history: use the editor’s own undo before you save.

Open outside yaggui

The Open outside yaggui menu in the diff toolbar offers:

Item	Effect
Open in the external diff tool	Runs git difftool --no-prompt --tool=<tool> (--gui when only diff.guitool is set) on this file and waits until the tool closes. Staged diffs add --cached; commit diffs pass the two commits. Disabled while the tool is open
Open in the editor	Opens the working-tree file in your editor (preference Editor, otherwise the system default)
Show in the file manager	Reveals the file in Finder or Explorer; on Linux, opens its folder

The editor and file-manager items always act on the working-tree file, even from a commit diff, and are disabled when the file no longer exists there. The diff tool is the Diff tool preference, otherwise Git’s diff.tool, otherwise diff.guitool. The palette action Open the current file in the external diff tool does the same as the first item. Set these tools in External tools.

Errors:

• “No external diff tool is configured: choose one in the preferences (Tools) or set diff.tool in your Git configuration.”
• “The diff tool "{tool}" could not be started. Check that it is installed and configured (difftool.{tool}.cmd).” The command log shows Git’s output.
• “The editor "{name}" could not be started. Check its name in the preferences.”