When Kiro proposes file changes, it displays them using a built-in diff tool. If you prefer a different diff experience—whether that's syntax highlighting, side-by-side views, or your favorite GUI tool—you can configure Kiro to use an external diff tool instead.
Configure your preferred diff tool with the chat.diffTool setting:
kiro-cli settings chat.diffTool <tool-name>
For example, to use delta:
kiro-cli settings chat.diffTool delta
To reset to the built-in diff:
kiro-cli settings -d chat.diffTool
These tools display diffs directly in your terminal, keeping you in your workflow:
| Tool | Config value | Best for |
|---|---|---|
| delta | delta | Git users who want syntax highlighting and line numbers |
| difftastic | difft | Language-aware structural diffs that ignore formatting |
| icdiff | icdiff | Quick side-by-side colored comparisons |
| diff-so-fancy | diff-so-fancy | Clean, human-readable output |
| colordiff | colordiff | Simple colorized diffs |
| diff-highlight | diff-highlight | Word-level highlighting (ships with Git) |
| ydiff | ydiff | Side-by-side with word-level highlighting |
| bat | bat | Syntax highlighting with Git integration |
These open a separate window for reviewing changes:
| Tool | Config value |
|---|---|
| VS Code | code |
| VSCodium | codium |
| Meld | meld |
| KDiff3 | kdiff3 |
| FileMerge (macOS) | opendiff |
| Vim | vimdiff or vim |
| Neovim | nvim |
You can customize tool behavior by including arguments in quotes:
# Enable side-by-side view in delta kiro-cli settings chat.diffTool "delta --side-by-side"
Kiro can work with diff tools not listed above. When you configure a tool, Kiro tries two approaches:
- Pipes a unified diff to the tool via stdin
- Invokes the tool with two temporary file paths as arguments
If neither approach works, Kiro falls back to the built-in inline diff.
If you see the error "Couldn't find the diff tool", the tool isn't installed or isn't in your PATH. Verify the tool is accessible:
which delta
If nothing is returned, install the tool first. For example, to install delta:
# macOS brew install git-delta # Ubuntu/Debian sudo apt install git-delta
For other tools, check the tool's documentation for installation instructions.
Custom Diff Tools