How to Diff Two Files with Git

Your working copy against the last commit

Plain git diff shows unstaged changes; git diff --staged shows what is about to be committed; git diff HEAD shows both together. Add a path to limit the output to one file.

$ git diff -- src/app.js
$ git diff --staged -- src/app.js
$ git diff HEAD~3 -- src/app.js   # against three commits ago

The same file in two branches or commits

Name both revisions, then the path. Two dots compare the tips; three dots compare the second against the common ancestor, which is what a pull request shows.

$ git diff main..feature -- config/app.yaml
$ git diff main...feature -- config/app.yaml
$ git diff a1b2c3d 9f8e7d6 -- README.md

Two files that are not in Git at all

--no-index turns git diff into a general-purpose diff with Git's colouring and pager, for any two paths on disk.

$ git diff --no-index app.conf app.conf.new

Word-level and statistics

--word-diff or --color-words highlights changed words instead of whole lines, which is far more readable for prose and long lines. --stat summarises how many lines changed per file, and -w ignores whitespace.

$ git diff --color-words -- docs/guide.md
$ git diff --stat main..feature

Open the diff in a visual tool

git difftool launches your configured tool (VS Code, meld, Beyond Compare) for each changed file. Set it once with git config --global diff.tool vscode and the matching difftool.vscode.cmd, then git difftool works everywhere git diff does.

$ git config --global diff.tool vscode
$ git config --global difftool.vscode.cmd 'code --wait --diff $LOCAL $REMOTE'
$ git difftool main..feature -- src/app.js

FAQ