Diff Checker
Text ToolsCompare two blocks of text and highlight what changed.
Original
Changed
Differences
Paste text into both boxes above. Additions appear in green and deletions in red. Switch between line-by-line and word-by-word comparison with the selector.
Compared entirely in your browser — your text never leaves your device.
What is Diff Checker?
Diff Checker compares two blocks of text and highlights exactly what changed between them — additions in green, deletions in red. Paste an original version on the left and a revised version on the right, then choose line-by-line or word-by-word comparison to see the edits at the level of detail you need. A running summary counts how much was added and removed, and because the whole comparison runs in your browser, neither version is ever uploaded.
How to use Diff Checker
Paste both versions
Put the original text in the left box and the changed text in the right box, or click Load sample to see how it works. The differences appear underneath as you type.
Choose the comparison level
Pick Line by line to compare whole lines — great for code, lists, and configs — or Word by word to spot small wording changes within a paragraph.
Read the highlights
Green marks text that was added in the changed version; red marks text that was removed from the original. Unchanged text stays in the normal color.
Check the summary
The Differences header shows a +added / -removed count so you can gauge the size of the change at a glance. Identical texts report no differences.
Common uses
- Review edits between two drafts of an article or email
- Compare two versions of a code snippet or config file
- See what a collaborator changed in a shared document
- Spot accidental changes before pasting text somewhere important
- Check translations or rewrites against the original wording
- Audit terms, contracts, or policies for altered clauses
Why choose FreeTools
100% private
Your files are processed inside your browser and are never uploaded to a server.
Free, no account
No sign-up, no watermark, no paywalled “premium” tier. Just open a tool and use it.
Instant
No upload, no queue, no server round-trip — work starts the moment you drop a file.
Runs in your browser
Built on open web standards. Works on any modern desktop browser, nothing to install.
No upload size caps
Nothing leaves your device, so there’s no server file-size limit — only your machine’s memory.
Yours to keep
Results download straight to your device in clean, standard file formats.