How can I compare a Git tag with the current working tree?
Quick answer
Run git diff TAG, replacing TAG with the tag you want to inspect—for example, git diff v1.0. This compares that tagged commit with your current working tree; you do not need to check out the tag. Read the direction as changes from the tag to your working tree. To reverse the diff direction, use git diff -R TAG. [S1]
The question, the details, the next step.
I want to see what my files look like now compared with a release tag. What command should I use, and do I need to switch to the tag first?
Use git diff TAG, substituting the tag name you intend to compare. For example:
git diff v1.0
This compares the tagged commit with your current working tree; you do not need to check out the tag. It is a comparison, not a request to move your branch or replace your current files. [S1]
Read the direction as showing how the working tree differs from v1.0. Git documents this form as comparing a commit with the working tree. [S1]
How do I make sure I pick the right tag and understand which side is which?
Choose the tag that represents the version you want as your baseline, then put that tag after git diff. The endpoint order determines the comparison direction, so pause before reading the output: with git diff v1.0, the baseline is v1.0 and the other endpoint is your working tree. [S1]
A useful mental prompt is: “What changed between the tagged version and the files I have here?” If instead you want the reverse presentation, use git diff -R v1.0. That reverses the diff direction; you do not need to check out the tag. [S1]
Could you show a small example of reviewing changes since a tag?
Suppose v1.0 is your chosen baseline and you want to compare it with the current project. Run:
git diff v1.0
The command compares the tagged version with your current working tree, so inspect the output as differences from the tag to the files you have now. [S1] If the direction looks opposite to the question you are asking, reconsider the comparison direction or use the reverse-diff option rather than assuming the output means “changes since” in the direction you intended.
What should I do before relying on the result, and what does this comparison not tell me?
Confirm the tag name and the direction you intend, then run the diff and inspect its output. If your question is what differs between the tag and the files currently in your working tree, git diff TAG is the direct comparison. [S1]
A diff shows differences between its endpoints; by itself, it does not establish why a change happened, whether it was intended, or whether it is correct. Use the output to identify what to review, not as an explanation of the changes.
A practical checklist
Choose the tag that represents the version you want as your baseline.
Use
git diff TAGto compare that tag with your current working tree.Read the direction explicitly: the tag is compared with the working tree.
Use
git diff -R TAGwhen you want the reverse diff direction.Treat the output as differences to review, not an explanation of why they exist.
A few more useful answers
Will `git diff TAG` check out the tag or move my branch?
No checkout is needed for this comparison. The documented diff form compares a tag’s commit with the working tree without requiring you to check out the tag. [S1]
How do I reverse the comparison direction?
Use git diff -R TAG to reverse the diff direction. Check the direction before interpreting which endpoint a displayed change represents. [S1]
Does the diff explain whether a change is good or intentional?
No. It shows differences between the selected endpoints; deciding why a change exists or whether it is appropriate requires reviewing it in context.
Sources
References used for this guide.
- [S1] Git - git-diff Documentation git-scm.com · Checked