Can I use this instead of GitHub's diff view?

This tool is a supplement to, not a replacement for, your git platform's diff view. It is useful when you need to review code outside of git, when the platform diff is hard to read, or when you want a clean view for discussion or documentation.

Does it detect moved code?

The diff algorithm detects line-level additions and removals. Code that is moved from one location to another will appear as deleted from the old location and added at the new location.

Can I copy the diff output?

You can select and copy text from the diff view. For sharing, a screenshot of the syntax-highlighted diff is often the most readable format.

What diff algorithm does it use?

The tool uses the diff-match-patch library for reliable diffing, combined with highlight.js for syntax highlighting across 50+ languages.

Code Diff Viewer for Pull Request Review

Review Code Changes5 credits

Not every pull request review happens in GitHub or GitLab. Sometimes you receive code changes via email, a shared document, or a chat message. Sometimes the diff in your git platform is hard to read because of rebasing or large file changes. Sometimes you just want a clean, distraction-free view of what changed.

This code diff viewer gives you a professional, syntax-highlighted comparison of any two code snippets. Paste the original and modified code, select the language, and review in either side-by-side or unified view. Supports 50+ programming languages.

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Features

50+ Language Support

Syntax highlighting for JavaScript, TypeScript, Python, Go, Rust, Java, C#, PHP, Ruby, SQL, and many more.

Side-by-Side View

Review original and modified code in parallel columns so you never lose context.

Private Review

Code stays in your browser. Nothing is sent to any server — safe for proprietary codebases.

How It Works

Paste the original code

Copy the original function, file, or snippet and paste it in the left panel.

Paste the modified code

Copy the updated version and paste it in the right panel.

Select the language

Choose the programming language for accurate syntax highlighting.

Review the diff

Changed lines are highlighted with green (added) and red (removed). Review in split or unified view.

Better Code Review with Visual Diffs

Effective code review requires understanding not just what changed, but why. Syntax-highlighted diffs make it easier to read the modified code as actual code — with proper coloring for keywords, strings, comments, and operators — rather than as raw text with colored backgrounds.

This tool is especially useful for reviewing code changes shared outside of a git platform: code sent in a Slack message, pasted in a Jira ticket, included in a design document, or received from a contractor who is not on your repository. It is also helpful for reviewing large refactors where the git diff is noisy due to file moves and renames.

For mentoring and code review training, this tool provides a clean interface for discussing specific changes without the overhead of setting up a full repository and pull request.

Practical Checklist

Start with the right input

Bring the code, data, markup, URL, or technical file that matches this use case. For code diff viewer for pull request review, a focused source gives Code Diff Viewer a clearer job and makes the result easier to review.

Use the result in context

Verify formatting, edge cases, and generated output before pasting it elsewhere, then match the output to the final destination before exporting or copying it.

Move it into your workflow

Once the output is ready, copy or download the result for your repo, ticket, documentation, or handoff. Keep the original source nearby so you can rerun the tool if requirements change.

Frequently Asked Questions

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Looking for the full-featured tool?

View Code Diff Viewer