Text Compare (also called a diff checker) shows the differences between two pieces of text. Paste an original and a revised version of a contract, essay, configuration file, code snippet or list, and the tool highlights every line that was added or removed.
It uses the same longest-common-subsequence approach as professional diff tools, so moved or edited lines are matched sensibly. Added lines are shown in green, removed lines in red, and unchanged lines in plain text.
How to use the Text Compare tool
- Paste the original text on the left.
- Paste the changed text on the right.
- Choose whether to ignore case or extra spaces.
- Click Compare and review the highlighted differences.
Features
- Line-by-line diff with colour highlighting.
- Options to ignore letter case and surrounding whitespace.
- Summary count of added and removed lines.
- Handles documents, code, CSV data and lists.
- Private: both texts stay in your browser.
Tips for best results
A line that was edited shows up as one removed line (red) followed by one added line (green). Compare them side by side to spot the exact change. To compare two lists regardless of order, sort both first, or remove repeated entries with Remove Duplicate Lines.
Spotting a change between two versions by eye is slow and unreliable, especially in long documents where one word or number has changed. A diff tool shows every change at once, which is why writers, editors, lawyers, translators and programmers use one to review revisions before approving them.
Compatibility and limits
The Text Compare tool works in every modern browser on desktop and mobile and handles very long texts, even entire books, without slowing down. It understands Unicode, so it works with English as well as Urdu, Arabic, Hindi, Chinese, emoji and accented letters. Because nothing is sent over the network, results appear instantly as you type or click.
Privacy: your files never leave your device
Everything you type or paste is processed instantly in your browser. Your text is never sent to a server, logged or stored, so it's safe to use with drafts, private notes and confidential documents.
Frequently asked questions
How does the text compare tool work?
It finds the longest sequence of lines common to both texts and marks everything else as added or removed.
Can I compare code?
Yes. Monospace display and whitespace options make it handy for code and config files.
Is there a size limit?
It handles up to about 5,000 lines per side comfortably in the browser.
Is my text uploaded?
No. The comparison runs entirely in your browser.
Can it compare Word or PDF files?
Paste the text from them. You can extract PDF text with our PDF to Text tool.