Markdown Diff Viewer

Compare two Markdown documents side by side with colored diff highlighting. See additions, deletions, and changes instantly. Free and private.

Paste your original Markdown on the left and the modified version on the right, then click Compare to see a colour-coded diff.
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Paste two versions of your Markdown above and click Compare to see what changed.

How It Works

  1. Paste your original Markdown

    Copy the original version of your document and paste it into the left-hand Original pane.

  2. Paste your modified Markdown

    Copy the updated version of your document and paste it into the right-hand Modified pane.

  3. Click Compare and review changes

    Hit the Compare button to generate the diff. Green highlights show additions; red strikethrough shows deletions. A summary at the top counts total added and removed characters.

Frequently Asked Questions

Why Use a Markdown Diff Viewer?

Whether you are collaborating on documentation, reviewing a colleague's edits, or just tracking your own revisions, being able to see exactly what changed between two versions of a Markdown file saves time and prevents errors. A dedicated diff viewer makes changes impossible to miss — no more reading both files line by line hoping you spotted everything.

How the Diff Algorithm Works

Under the hood this tool uses the diff-match-patch algorithm, originally developed at Google. It operates at the character level and applies semantic cleanup to produce diffs that align with natural word and sentence boundaries. This means the output reads like a human-reviewed edit rather than a mechanical character comparison.

After the initial diff is computed, a semantic cleanup pass merges small nearby changes into larger, more readable hunks. The result is a single inline view where green spans represent inserted text and red strikethrough spans represent deleted text — all in the context of the surrounding unchanged content.

Common Use Cases

  • Documentation reviews: Compare a draft README or wiki page against a revised version before merging a pull request.
  • Writing and editing: Track changes between drafts of a blog post, article, or technical specification.
  • Collaboration: Share a before-and-after diff with teammates who need to understand what changed without reading the whole document.
  • Content migrations: Verify that an automated conversion or reformatting script only changed what it was supposed to.

Privacy First

All diffing happens directly in your browser. No text is ever transmitted to a server, stored in a database, or logged. You can safely compare proprietary documentation, internal specs, or any sensitive material without worrying about data leaks.

Tips for Better Diffs

For the clearest results, make sure both documents use consistent line endings. If you are copying from a Git diff or a code editor, strip any leading + or - diff markers before pasting. Running both documents through the Markdown Formatter first also helps by normalising whitespace and list markers, so the diff highlights only meaningful content changes.