Results are provided for informational purposes only and may contain errors. Please verify important information independently. Use of this tool is at your own risk.
What the Text Diff Checker does
The Text Diff Checker compares two versions of a text and highlights what changed: removed text in red, added text in green and unchanged text as it was. Paste the original on one side and the new version on the other, then press Compare. Line-by-line mode treats each line as a unit, which suits code, configs and lists; Word-by-word mode highlights the exact words that changed inside a paragraph. Character-by-character mode marks the exact letters that changed, which helps with typos, IDs and codes.
The comparison uses the Myers diff algorithm, the same approach behind git diff, and shows the smallest set of changes. Texts of up to one million characters are accepted. When two very large texts differ in thousands of places, the result keeps the common start and end exact and marks the changed middle as one removed and one added block, so the answer arrives quickly instead of timing out.
When to use it
- Checking what changed between two versions of a contract, article or translation.
- Comparing two config files or environment files that should be almost identical.
- Reviewing an edit when you do not have Git history, for example text from a CMS.
- Comparing two API responses after formatting both with the JSON Formatter & Beautifier.
Worked example
Input
The deploy runs at 9:00.
It uses the staging database.
Notify the team on Slack.
---
The deploy runs at 9:00.
It uses the production database.
Notify the team on Slack.Output
The deploy runs at 9:00.
- It uses the staging database.
+ It uses the production database.
Notify the team on Slack.Common questions about the Text Diff Checker
Which mode should I use?
Use line-by-line for code, data and lists, where whole lines are added or removed. Use word-by-word for prose, where a sentence changes by a word or two and you want to see exactly which ones.
Why does a whole line show as changed when I only added a space?
In line mode any difference makes the line different, including trailing spaces and tabs. Run both texts through the Whitespace & Line Trimmer first if whitespace changes do not matter to you.
Is my text stored?
The comparison runs entirely in your browser: the two texts are never sent to a server, stored or logged.
Can I compare two lists regardless of order?
A diff is order-sensitive. Sort and deduplicate both lists with the Line Sorter & Deduplicator first; then only the items that exist in one list will be marked.
Is this tool free?
Yes, it's free to use. No signup, no email required. Get results on this page.
How do I get my result?
Use the tool on this page. Your result appears here; no email delivery is required.