Free Text Diff Checker — compare two texts, down to the word
Paste or upload two texts and see every difference: line-by-line with word-level highlights, live as you type, with a .patch and HTML report export. 100% private — nothing is uploaded.
How it works
-
Paste or drop two texts
Type, paste, or upload files — plain text, Markdown, CSV, or code. Everything stays in your browser.
-
See every difference, precisely
A two-pass diff: lines first, then word-level highlights inside changed lines — the same approach code-review tools use. Unchanged runs fold away so you see only what matters.
-
Edit live, then export
The diff updates as you type. Export a unified .patch file, a standalone HTML report, or read the changed-values table with computed deltas.
A diff you can trust, not a highlighter
Most online text comparers highlight whole lines and call it a day. This tool runs the same two-pass comparison code-review tools use: a line-level diff first (the Myers algorithm, via the same open-source library the Monity monitoring engine runs in production), then a word-level pass inside every changed line. The result: when one word changes in a paragraph, you see that word — not a wall of red.
Built for real working sessions
- Live re-compare — after the first comparison, the diff updates as you type. Fix a line, watch it turn white.
- Context folding — long unchanged stretches collapse to a single expandable row, so a 2,000-line file with three edits reads in seconds.
- Ignore case & whitespace — instantly discard formatting noise when comparing reformatted code or copy from different sources. Free, not paywalled.
- Changed values — every number that changed is extracted into a table with its computed delta ($1,200 → $1,450, +20.8%). For anyone comparing two versions of a report, that table is the answer.
- Side-by-side or inline — synced line numbers in both views, monospace rendering, and empty-line handling that doesn't lie to you.
Export the evidence
One click downloads a unified .patch file — the standard format git, IDEs, and every code tool understand — or a self-contained HTML report of the full side-by-side diff, ready to attach to an email, a ticket, or an audit file. Like the comparison itself, exports are generated entirely in your browser.
Private by design
Nothing you paste here leaves your machine. There is no upload, no storage, no account, and no "share" feature quietly putting your text on a server. Compare contracts, source code, and unpublished drafts with a clear conscience — close the tab and it's gone.
The same diff, running 24/7
This is the manual version of what Monity does automatically: it watches any web page and diffs its text on every check, alerting you the moment something changes — with the same word-level precision you see here. The free plan watches 3 pages, forever.
FAQ
Common questions
Is my text uploaded anywhere?
No. Both texts are compared entirely in your browser — nothing is sent to Monity or any server, and there's no account. That makes it safe for contracts, source code, unpublished copy, and anything confidential.
How precise is the comparison?
It's a two-pass diff, the same approach GitHub uses for code review: a line-level comparison first (using the Myers algorithm via the battle-tested jsdiff library — the same library the Monity monitoring engine runs in production), then a word-level pass inside each changed line, so the highlight lands on the exact words that changed rather than the whole line.
Can I ignore case or whitespace differences?
Yes — both toggles are free and apply instantly. Ignore case treats "Total" and "total" as equal; ignore whitespace collapses spacing and indentation differences, which is ideal for comparing reformatted code or copy pasted from different sources.
What can I export?
A unified .patch file (the standard format git and every code tool understands), and a standalone HTML report with the full side-by-side diff — self-contained, ready to attach to an email or an audit file. Numbers that changed are also extracted into a table with computed deltas.
Can I monitor a page's text for changes automatically?
Yes — that's exactly what Monity does. It watches any web page, runs this same kind of diff on every check, and alerts you in Slack, Teams, or email the moment the text changes. The free plan includes 3 monitors forever.
Diffing text by hand?
Monity does it on every change.
Monity watches any page and shows you this exact kind of diff the moment its text changes — in Slack, Teams, or email.
- Free 7-day trial
- No credit card
- 3 monitors free, forever