How In-Browser Text Comparison & Diff Checking Works
Text Diff & Comparison Checker runs entirely in your browser with JavaScript. There is no sign-up, and whatever you type or open here is processed on your device instead of being sent to a server.
Compare Two Texts Privately in Your Browser
Find differences, additions, and deletions between two drafts, contract versions, or code snippets. Diff calculation runs 100% on-device in browser memory using the Myers diff algorithm, ensuring legal contracts, source code, and private documents never leak across the network.
Exact Line-by-Line Difference Highlighting
Inspect changed, inserted, and deleted lines with clear color-coded indicators (green for additions, red for removals). The diff engine lines up thousands of lines quickly when the changes are few. If two texts differ in too many places (roughly 2,000 added or removed lines), it shows the changed part as removed and then added, with a note. Lines must match exactly, so an extra space at the end of a line or a change in capital letters makes the line count as changed.
Summary Metrics of Added and Removed Lines
View exact counts of total added, deleted, and unchanged lines alongside visual diff markers, making document revisions easy to review.
Why processing in your browser matters
Many online tools upload your files or text to a server to process them. This one does the work on your computer or phone, so your data is not sent to us or stored anywhere else. That lowers the risk when you work with confidential material, although you should still follow your organisation's own rules. Read how this works in our Privacy Policy.
- No uploads: files are opened and saved on your device, so there is no upload or download wait.
- No account: nothing to sign up for or install.
- Free to use: no subscriptions or paywalls.