Markdown Diff Tool — Compare Two Markdown Files Online
Compare two markdown files side by side
How markdown diff works
Paste two versions of a markdown document into the left and right panes. The tool highlights additions in green and deletions in red — at both line level and word level.
Switch between raw diff (markdown source) and rendered diff (formatted output) to review changes in context.
Features
- Word-level diff highlighting
- Line-level diff highlighting
- Raw markdown and rendered views
- Side-by-side comparison layout
- No upload — everything runs in your browser
When to use it
- Reviewing AI-generated documentation changes
- Comparing markdown versions before merging a PR
- Checking what changed between two CLAUDE.md revisions
- Auditing edits to runbooks or system prompts
Frequently asked questions
Quick answers about raw versus rendered diffs, word-level change tracking, and privacy.
How do I compare two markdown files online?
Paste the original version in the left pane and the updated version in the right pane. The tool immediately highlights additions in green and deletions in red, at both line and word level.
Does the markdown diff tool support word-level differences?
Yes. In addition to line-level highlighting, the tool highlights the exact words that changed within each modified line, so you can pinpoint small edits quickly.
Are my documents uploaded to a server when I compare them?
No. All diffing runs in your browser using the diff npm library. Your documents are never sent to a server.
Can I see the diff in rendered markdown, not just raw source?
Yes. Toggle between Raw diff (markdown source with highlights) and Rendered diff (formatted output) using the view switcher above the diff panel.
After reviewing, use the Markdown Formatter to normalise the result, or export to PDF.