Track Changes Editor
Edit a text and show every change as a redline — accept or reject each one, comment, and share it all as a link
How it works
Paste the text you were given into Original. The Revision pane mirrors it until you start editing there — edit freely, and the Changes panel below shows the result as a redline: deleted text struck through in red, inserted text underlined in green, a replacement as the two together, in the revision's reading order and with the paragraphs kept. Compare by words (the usual choice for prose), characters (for spelling corrections), sentences or lines, and optionally ignore whitespace changes so reflowed text is not marked. Click any change, or move through them with the arrow keys, to accept it (the original takes the change and the mark disappears), reject it (the revision goes back to what the original said there) or attach a comment, which appears as a numbered marker; Accept all, Reject all and Undo cover the rest, and the List shows every change in order with its comment. Side by side shows the original with its deletions next to the revision with its insertions; Final shows the clean text as it stands. Add your name and a note to the author, then Share: the link carries both texts, every comment and the note, compressed, so whoever opens it sees the same redline and can accept or reject each change in turn — long links are shortened automatically. Export copies the final text, the redline as rich text (it pastes into Word, Google Docs, Pages or an email with the strikethrough and underline intact), as Markdown (~~deleted~~ and **inserted**, comments as footnotes) or as plain markup ([-deleted-]{+inserted+}), and downloads or prints a standalone HTML page with the summary, the note, the redline and the numbered comments. The draft is saved in your browser as you work. Nothing is uploaded.
Questions
How is this different from the Diff Checker?
The Diff Checker compares two texts and shows a developer's diff — lines, hunks, patches. Track Changes is for editing prose: you edit the revision in place, the result reads like a redlined document, and each change can be accepted, rejected and commented on, as in a word processor's Track Changes. Use it for reviews, proofreading, contracts and any text where the author needs to see and decide on every edit.
How do I accept or reject a change?
Click the change in the redline (or a row in the List), then press Accept or Reject in the bar above it — or use the keyboard: ← and → move between changes, a accepts, r rejects, c opens the comment. Accepting folds the change into the original so it stops being a change; rejecting puts the original wording back into the revision. Accept all and Reject all decide everything at once, and Undo takes any decision back.
How do I send my edits to the author?
Press Share. The link holds the original, your revision, your comments, your name and your note, compressed into the address, and it is shortened automatically when long. The author opens it in any browser, sees the same redline, and accepts or rejects each change; they can share the result back the same way.
Can I paste the redline into Word, Google Docs or an email?
Yes. Export → Copy redline (rich text) puts the marked-up text on the clipboard with real strikethrough and underline formatting, which Word, Google Docs, Pages, Outlook and Gmail keep when you paste. Copy Markdown gives ~~deleted~~ and **inserted** with comments as footnotes for GitHub, Notion or Obsidian, and the .html download or Print gives a page with the summary, your note and the numbered comments.
What do words, characters, sentences and lines change?
The unit the two texts are compared in. Words marks the words that differ and keeps punctuation separate; it suits almost all prose. Characters marks single letters, which shows a spelling correction as the letters that changed. Sentences and lines mark whole sentences or lines, a coarser view for heavily rewritten text. Ignore whitespace changes (words only) stops reflowed paragraphs and doubled spaces from counting as edits.
Is my text private?
Yes. The comparison runs in your browser and the draft is saved only there. Text leaves your device only inside a link you make with Share, and a shortened link is just a pointer to that same link.