Character Counter
A character counter is a tool that counts every letter, number, space and symbol in a text. Characters with…
Free text compare tool
Paste an original and a changed version to see every added and removed word.
Result
0Added
0Removed
0%Similarity
Left: original with removed text struck through in red. Right: changed text with additions underlined in green.
The free text compare runs in your browser, needs no sign-up and never sends what you type anywhere.
Quick answer
This text compare tool highlights the differences between two texts word by word or line by line, showing removed text in red on the left and added text in green on the right. Use word mode for edited copy and meta tags, and line mode for lists, robots.txt files and code.
What is a text compare tool?
A text compare tool, or diff checker, is a tool that finds the smallest set of additions and deletions that turns one text into another. It uses the longest common subsequence: words both versions share stay plain, and everything else is marked as removed or added.
How do you use the Text Compare Tool?
- Paste the original text in the left box.
- Paste the changed text in the right box.
- Choose word by word or line by line comparison.
- Tick Ignore case if capitalization changes do not matter.
- Review the highlighted removed and added text and the similarity score.
How do I compare two texts for differences?
Paste the original in one box and the new version in the other, and the tool highlights every change. Removed words are struck through in red on the left and added words are underlined in green on the right, so you can review edits in seconds instead of reading both versions.
Can I use text compare to check for duplicate content?
Yes, for two specific texts. A similarity score above about 80% means the pages are largely the same. Google's spam policies list lightly reworded copied content as scraped content, so pages need original value, not just swapped words.
What is the difference between word and line comparison?
Word comparison treats each word as a unit, which is best for prose, titles and meta descriptions. Line comparison treats each line as a unit, which is best for lists, code, robots.txt and sitemap URL lists where one changed line matters.
Quick reference
| Use case | Mode | What to look for |
|---|---|---|
| Edited blog post | Words | Removed facts and added claims |
| Title and meta description tests | Words | Keyword moved or dropped |
| robots.txt before and after | Lines | New Disallow rules |
| URL or keyword lists | Lines | Added and removed items |
| Writer or AI rewrite vs source | Words | Similarity above 80% means too close |
Worked example
Example
Example: the original meta description "Buy cheap guest posts on high DA sites today" and the new one "Buy quality guest posts on relevant high DA sites" share 7 words. The tool marks "cheap" and "today" as removed and "quality" and "relevant" as added, a similarity of 2 x 7 / (9 + 9) = 78%.
Frequently asked questions
How is the similarity score calculated?
Similarity is twice the number of unchanged words or lines divided by the total in both texts, times 100. Two identical texts score 100% and two texts with nothing in common score 0%. Ignore case raises the score when only capitalization changed.
Is there a size limit for comparing texts?
The tool compares up to about 2,000 changed words or lines per side after skipping the identical start and end of both texts. That covers long articles. For very large files, compare one section at a time.
Does the tool show moved paragraphs?
A moved block shows as removed in its old place and added in its new place, because the comparison follows the order of the text. If a large section appears both removed and added, it was probably moved rather than rewritten.
Can I compare code with this tool?
Yes. Use line mode for code, configuration files and robots.txt files, so each changed line is highlighted. Spaces inside a line are compared exactly in line mode, so an indentation change marks the line as changed.
Why are punctuation changes shown as word changes?
Punctuation is attached to the word it touches, so changing "sites" to "sites." marks the whole word as removed and added. This keeps the output readable and still shows you exactly where the edit happened.
Are my texts uploaded to compare them?
No. The comparison runs in your browser with JavaScript. Neither text is uploaded, stored or logged, so you can safely compare contracts, client drafts and unpublished content.
Sources
Facts checked against these official pages. Read how I check facts in my editorial policy.
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