Markdown Diff
Paste two versions of a document and instantly see what changed — line, word, or character granularity, inline or side-by-side, with additions and deletions highlighted.
Runs entirely in your browser — files never leave your device.
- # Release Notes — v2.3+ # Release Notes — v2.4## Highlights- - Faster cold start (down to 400ms)+ - Faster cold start (down to 250ms)- Dark mode is now the default theme- Fixed a bug where exports could time out on large files+ - Added keyboard shortcuts for common actions## Known issues- Search results occasionally miss recently added tags+ - Printing from Safari can clip the last page
How it works
- 01Paste the original document into the left pane and the changed version into the right pane, or click Sample to try a realistic release-notes diff.
- 02The diff pane below updates automatically as you type in either pane.
- 03Switch between Line, Word, and Char granularity — line mode highlights whole changed lines, word mode highlights only the changed words, and char mode narrows down to the exact changed characters (useful for spotting a single-letter typo fix).
- 04Switch between Inline and Side-by-side view — side-by-side lays the two documents out in aligned columns, with a modified line's word/char-level changes highlighted inline in both columns.
- 05Toggle "Ignore whitespace" to treat lines/words that only differ in spacing (trailing spaces, extra spaces between words) as unchanged.
- 06Copy the diff as unified-diff-style text, or download it as a .patch file.
Frequently asked questions
Is this Markdown diff tool free?
Yes, with no account or limits. Every diff granularity (line, word, character) runs entirely in your browser's JavaScript engine.
Do my documents get uploaded anywhere?
No. The comparison happens entirely client-side — neither document ever leaves your device, and nothing is sent to a server.
What's the difference between line, word, and char mode?
Line mode compares whole lines, so a one-word edit still highlights the entire line as changed — useful for spotting reordered or restructured content. Word mode compares individual words within a line, so a small edit to a sentence only highlights the words that actually changed. Char mode goes further still, highlighting only the exact characters that changed — ideal for spotting a typo fix or a single-character edit inside a longer word.
What's the difference between Inline and Side-by-side view?
Inline view shows one combined stream with removed lines/words struck through and added ones highlighted, in document order. Side-by-side view lays the original and changed documents out in two aligned columns — closer to what most code review tools show — with modified lines paired up and their word/char-level changes highlighted inline in both columns.
What does "Ignore whitespace" do?
It treats two lines, words, or characters that differ only in spacing — trailing spaces, or extra spaces between words — as unchanged, so reformatting-only edits don't clutter the diff. The comparison is whitespace-insensitive; what's displayed is always real, unmodified text from one of your two documents.
Does this work on plain text, not just Markdown?
Yes — the diff algorithm doesn't parse Markdown syntax at all, so it works equally well on plain text, code, or any other text-based content.
Can I get a standard unified diff format?
Yes — the Copy and Download buttons produce a unified-diff-style output with +/- line prefixes, independent of whichever granularity, view, or ignore-whitespace setting you currently have selected.