Text Diff Checker
Compare two or three texts side-by-side and instantly spot additions, deletions and changes — character, word or line level. Pull text from URLs or PDF / Word files, save history, 3-way merge. 100% private.
Recent comparisons
Fetch text from URL
Paste a public URL — we'll pull its raw text via a CORS proxy.
How to Use the Text Diff Checker
- Pick a mode — 2-Way Compare or 3-Way Merge (for combining two divergent edits over a common base).
- Add your texts — paste, type, drop a file (TXT, PDF, DOCX and more), or fetch from a URL.
- Choose granularity — Character (finest), Word (best for prose), or Line (best for code).
- Fine-tune options — ignore case, whitespace, blank lines; toggle line numbers, word wrap, sync scroll.
- Click "Compare Now" (or enable Auto-compare) to render the diff in real time.
- Navigate — jump between changes, search inside the diff, switch views, copy or export as HTML / patch / JSON / PDF.
- Save & share — every comparison is auto-saved to your local history; click Share to copy a self-contained link.
What is a Text Diff Checker?
A text diff checker takes two (or three) pieces of text and highlights exactly what changed — what was added, what was removed, what stayed the same. Instead of squinting at two versions side-by-side, you get a clean colour-coded report.
Our checker uses the proven Myers diff algorithm under the hood and runs entirely in your browser. That means even huge documents, source code or sensitive contracts never leave your device — and the comparison is virtually instant.
Common Use Cases
Why Choose Our Text Diff Checker
Frequently Asked Questions
Is my text uploaded anywhere?
No. Every comparison runs inside your browser. PDF and Word files are parsed locally too. The only optional network call is "Fetch from URL", which routes through a public CORS proxy purely to retrieve that URL's content — nothing of yours is uploaded.
Can I compare PDF or Word documents?
Yes. Upload or drop a .pdf or .docx file and the tool extracts its text in your browser so you can diff it like any other text. Formatting, images and layout are dropped — only the text content is compared, which is exactly what you want for spotting wording changes.
What is 3-way merge?
3-way merge is the technique Git uses. You provide a Base (common ancestor), Yours and Theirs. The tool merges both edits automatically where they don't overlap, and inserts standard <<<<<<</=======/>>>>>>> conflict markers where they do.
What's the difference between character, word and line diff?
Character compares every character — perfect for short strings. Word compares whole words and is best for prose. Line compares whole lines — ideal for source code, configs and logs.
Where is my history stored?
In your browser's localStorage only — the last 10 comparisons are kept on this device. No account, no cloud sync.
How big can my texts be?
Anything up to several megabytes works smoothly. Above ~10MB browsers slow down for any diff tool, so we cap file uploads at 10MB.
What does "Ignore whitespace" do?
It collapses runs of spaces and tabs so reformatted text or differently indented code isn't flagged as changed.
Can I share a comparison with a colleague?
Yes — click Share to copy a URL that encodes both texts and your view settings. Or Export as unified patch (.diff) to send a Git-style patch file.
Does it work on mobile?
Yes — the input panes stack vertically and all toolbars wrap responsively.