Text Diff
Paste two versions of text below, then click Compare to see differences highlighted. All processing is done locally in your browser.
What is Text Diff?
Text Diff is a free online text comparison tool that lets you compare two blocks of text side by side. It highlights additions, deletions, and unchanged parts so you can quickly spot what has changed. Ideal for reviewing code changes, proofreading document revisions, or comparing configuration files. Like all our tools, Text Diff runs entirely in your browser and never sends your data anywhere.
How to Compare Text Online
- Enter the original text: Paste the first version of your content into the "Original Text" box.
- Enter the modified text: Paste the second version into the "Modified Text" box.
- Choose diff mode: Select whether to compare word by word (great for prose) or line by line (better for code or lists).
- Click "Compare": The tool will compute the differences and display them in two separate panes. Removed parts are highlighted in red on the left, added parts in green on the right.
Common Use Cases for Text Diff
- Code review: Quickly see what lines were changed between two versions of a script or configuration file.
- Document proofreading: Compare a revised article with its original to ensure all intended edits were applied.
- Contract negotiation: Track changes between draft versions of legal or business documents.
- Academic writing: Compare manuscript versions after incorporating feedback.
- Data validation: Check that exported data matches the expected template.
Frequently Asked Questions
Is the comparison case‑sensitive?
Yes, the tool compares text exactly as you enter it. Differences in capitalization will be highlighted as changes.
Can I compare very large files?
The tool works best with texts up to a few thousand lines. For huge files, the browser may become slow; consider splitting the comparison into smaller chunks.
Are my texts private?
Absolutely. The diff algorithm runs in your browser. No data is transmitted over the network.
What diff algorithm is used?
We use a well‑established JavaScript library (diff) that implements Myers' diff algorithm for both word‑ and line‑level comparisons, providing accurate and fast results.