How to Compare Two Texts and Find Differences

Updated: April 4, 2026

Whether you're reviewing code changes, comparing document versions, or checking config file updates, seeing the exact differences between two texts saves time and prevents mistakes. This guide shows you how to compare any two texts instantly in your browser.

When You Need Text Comparison

Reviewing what changed between two versions of a document
Comparing code before and after a refactor
Checking config file differences between environments
Verifying that a copy-edit only changed what it was supposed to
Finding differences in API responses or database exports

How to Compare Two Texts

Step 1: Open the tool

Go to the Diff Checker.

Step 2: Paste your texts

Paste the original text in the left panel and the modified text in the right panel. You can also click "Sample" to see an example with code changes.

Step 3: Click Compare

Click "Compare" to see the differences. Added lines are highlighted in green, removed lines in red, and unchanged lines in white. Line numbers are shown for both the original and modified text.

Step 4: Copy the diff

Click "Copy diff" to copy the result in unified diff format (with +/- prefixes). This format is widely used in code reviews and version control.

Tips

For best results, compare texts that are structurally similar. The tool works line by line, so reformatting text before comparing can create misleading diffs.
Use the stats bar (+added, -removed, unchanged) to quickly gauge how much changed.
If you're comparing JSON, format both inputs first with the JSON Formatter so the diff is meaningful.

FAQ

What kind of differences does it detect?

The tool compares line by line and highlights three types of changes: added lines (green), removed lines (red), and unchanged lines (white). It uses the same algorithm family as git diff.

Can I compare code with this tool?

Yes. The diff output uses a monospace font and preserves indentation, making it ideal for comparing code, config files, SQL queries, or any structured text.

Can I copy the diff output?

Yes. Click "Copy diff" to copy the result in unified diff format (with +/- prefixes). You can paste it into a code review, email, or save it as a .patch file.

Is my data uploaded to a server?

No. All comparison happens entirely in your browser using JavaScript. Your text never leaves your device.

Try It Now

Ready to compare? Open the Diff Checker — it works entirely in your browser with no sign-up required.