Compare Text — Diff Checker

Paste two texts, see a word/line diff side-by-side or inline. Fully local diffing - your text never leaves your browser.

Compare Text - Diff Checker is a fast, private way to see exactly what changed between two pieces of text. Paste your original text on the left, your changed text on the right, and get an instant word- or line-level diff, side-by-side or inline - no upload, no account, no page access. PRIVATE BY DESIGN Zero access to your browsing - no content scripts, no host permissions. It cannot read your open tabs or any page. Every byte of comparison happens locally, inside the popup, using a self-contained diff algorithm. The text you paste never leaves your browser. This extension collects no data of any kind - no analytics, no tracking, no telemetry. The only network traffic it ever makes is a purchase-verification check with ExtensionPay if you choose to upgrade. FREE, AND GENUINELY USEFUL • Paste any two texts and get a clean, highlighted diff - additions and removals are color-coded and easy to scan. • Choose line-level or word-level granularity depending on what you are comparing (a paragraph of prose vs. a line of config). • Side-by-side view for a classic two-column comparison, or unified/inline view for a compact git-diff-style stream. • Ignore-case and ignore-whitespace toggles for when formatting differences do not matter. • Copy a quick, readable text rendering of the diff with one click. • Large pastes are handled gracefully - the popup will not freeze, and you will see a clear notice if an input had to be truncated or a diff had to be simplified for performance. • Your view mode, granularity, toggles, and theme (light/dark/ system) are remembered between sessions. PREMIUM ($5 one-time) For anyone who compares text regularly: • Character-level refinement: see exactly which characters changed within a line or word, not just that the whole line changed. • Export a real unified diff (.patch) file content - the same format produced by git diff or diff -u - ready to hand to a patch tool or paste into a code review. • Saved diff history: name and save comparisons locally so you can revisit them later, without re-pasting both sides. No subscription, no account required - pay once, keep the features. Whether you are checking a contract redline, comparing two drafts, or spotting what changed in a config file, this is one popup that shows you the difference - without ever asking to see what else is on your screen.