Markdown Diff Checker
Spot changes fast — compare two Markdown versions side by side with line-by-line diffs. Browser-based, private, no install needed.
Original Markdown
Modified Markdown
Diff Report
Markdown Diff Examples
Compare two Markdown versions. Example:
Example: Plan with added item
Modified Markdown (added Item C):
Diff Report
Click the Sample button above to load more examples into the editors.
What Is the Markdown Diff Checker?
The Markdown Diff Checker compares two Markdown versions and shows line-by-line differences. The algorithm is inspired by the concept of edit distance. Paste the original in the left panel and the modified version in the middle; the right panel displays the diff report. The CommonMark spec and CommonMark define Markdown syntax.
This tool runs entirely in your browser. Nothing is sent to a server. Use Sample to load example diff data. For formatting or validation, use Markdown Formatter or Markdown Validator. For linting, use Markdown Linter.
How to Use This Tool
Paste Original and Modified
Paste the original Markdown in the left panel and the modified version in the middle. Use Sample to load example content. Use Clear to reset both.
Review the Diff Report
The right panel shows added, removed, and changed lines. Use this to review edits, track changes, or prepare patch notes.
Copy or Download Report
Use Copy or Download to save the diff report. For TOC generation from either version, use Markdown TOC Generator.
When the Markdown Diff Checker Helps
When comparing drafts, reviewing PRs on GitHub or GitLab, or tracking doc changes, the diff shows exactly what changed. The GFM spec defines Markdown. Great for documentation workflows, README updates, and content review. For linting style issues, use Markdown Linter. For conversion, use Markdown to HTML.
Frequently Asked Questions
Does this tool send my Markdown to a server?
No. The comparison runs entirely in your browser. Your Markdown content is never uploaded anywhere — it's safe for private documentation, unreleased content, or internal wikis.
Can I compare rendered Markdown or only raw text?
This tool compares the raw Markdown source text, not the rendered HTML output. This is more useful for editing — you see exactly which characters and formatting symbols changed.
How is this different from git diff?
git diff requires a git repository and command-line access. This tool works instantly in your browser with any two Markdown snippets — no version history or terminal needed.
What Markdown flavours does it support?
It compares plain text — so any Markdown flavour works: CommonMark, GitHub Flavored Markdown, or any other variant. The diff is on the raw text, not the parsed result.
Can I export as patch?
The report shows the diff. For a unified diff or patch format, you may need a separate diff tool or git diff.
Related Tools
Learn more: CommonMark, CommonMark spec, Markdown Guide, GFM, git diff, GitHub, W3C HTML.