Git Diff Viewer

How to Use the Git Diff Viewer

1. Copy your git diff — run git diff, git diff --staged, or git show in your terminal and copy the output.
2. Paste the diff into the input area above.
3. Choose a view mode — Unified View shows changes in a single column; Side-by-Side View places old and new versions next to each other.
4. Review the output — additions are highlighted in green, deletions in red, and context lines in gray. File headers and hunk markers are clearly labeled.

What This Tool Does

This Git Diff Viewer parses unified diff format output — the standard format produced by git diff, git show, git log -p, and patch files — and renders it as a color-coded, readable display with line numbers. Unlike a generic diff checker that compares two text inputs, this tool is specifically designed to parse and visualize pre-existing git diff output, making it ideal for reviewing pull request diffs, email patches, or terminal output in a more readable format.

Understanding Unified Diff Format

The unified diff format is the standard output of git diff. Each diff begins with file headers (--- a/file and +++ b/file) that identify the files being compared. Hunk headers (@@ -start,count +start,count @@) indicate which lines are shown. Within each hunk, lines prefixed with + are additions, lines with - are deletions, and unprefixed lines provide context. This tool parses all of these elements and renders them with appropriate color coding and line numbers.

Unified vs. Side-by-Side View

The unified view displays all changes in a single column, exactly matching the structure of git diff output but with color coding added. This is compact and familiar to developers who work in the terminal. The side-by-side view splits the display into two columns — the old file on the left and the new file on the right — making it easier to see exactly what changed on each line. Side-by-side is especially useful for reviewing large diffs where the context around changes matters. Both views show line numbers for easy reference when discussing changes in code reviews.

Common Git Diff Commands

• git diff — show unstaged changes in your working directory
• git diff --staged — show changes that are staged for the next commit
• git diff HEAD~1 — show changes in the last commit
• git diff main..feature — show changes between two branches
• git show abc1234 — show the diff for a specific commit
• git log -p -3 — show diffs for the last 3 commits
• git diff --stat — show a summary of changes (files and line counts)

When to Use a Diff Viewer

A visual diff viewer is essential during code reviews, debugging sessions, and release audits. When reviewing pull requests, pasting the diff into a viewer with color coding makes it significantly easier to spot problematic changes compared to reading raw terminal output. During debugging, comparing the diff between a working and broken commit helps isolate the exact change that introduced a bug. Before releases, reviewing the cumulative diff between the last release tag and the current branch gives you a clear picture of everything that will ship. This tool also handles patch files — if someone emails you a .patch file, you can paste its contents here for immediate visualization.

Tips for Working with Git Diffs

For the best experience, use git diff -U5 to include 5 lines of context (instead of the default 3) around each change — more context makes diffs easier to review. Use git diff --word-diff in your terminal for word-level highlighting, which is useful for prose changes. When reviewing large diffs, use git diff --stat first to see which files changed and how many lines were added or removed, then focus on the most impactful files. For ongoing development, consider using our Diff Checker to compare arbitrary text, or the JSON Formatter to clean up JSON before diffing.