How to compare two texts
- Paste the original version into the left box and the changed version into the right box.
- Click Compare to run the line-by-line diff.
- Review the result: removed lines are red with a − prefix, added lines are green with a + prefix. Click Copy diff to share it.
What do the colors mean?
The checker uses the classic diff convention. A red line with a “−” exists in the original but was removed in the new version. A green line with a “+” is new — it only exists in the changed version. Grey lines are identical in both texts and are shown for context, so you can see exactly where each change happens. The summary above the result counts every added, removed and unchanged line.
Common uses for a diff checker
Diffing is the fastest way to answer “what changed?”. Typical uses: comparing two versions of a contract or article before signing or publishing, checking what an editor or AI changed in your draft, spotting differences between two config files or code snippets, verifying a translation or transcription against the source, or deduplicating two nearly identical lists. Because the comparison is line-based, it works best on texts with natural line breaks.
Is it private and safe?
Yes. Toolyard compares your texts inside your browser on your own device. Nothing is ever uploaded to a server — safe for contracts, unpublished drafts, code and other confidential text.
Frequently asked questions
How does the text comparison work?
The checker compares the two texts line by line using a longest-common-subsequence algorithm, then highlights lines that were added in green and lines that were removed in red.
Can I compare code or documents?
Yes. Any plain text works — source code, configs, essays, contracts or lists. Paste both versions and click Compare.
Is my text uploaded?
No. The comparison runs entirely in your browser. Your text is never uploaded and stays private on your device.
Is it free?
Yes, completely free with no sign-up and no limits.