How to compare two texts
- Paste the original in the first box and the changed version in the second.
- Choose how to compare:
- Words (best for documents, essays and emails) shows exactly which words changed inside a sentence.
- Whole lines (best for code, lists and data) marks each changed line, like a programmer's diff.
- Characters (best for IDs, codes and short strings) spots a single changed letter or digit.
- Tick Ignore extra spaces or Ignore upper/lower case if those differences don't matter to you.
The result updates as you type, so you can also use it to check edits as you make them.
How the comparison works
The tool finds the longest common subsequence: the largest set of words that appear in both texts in the same order. Everything else is either a removal (in the original only) or an addition (in the new version only). This is the same idea used by tools like diff and Git. To stay fast with long documents, it compares lines first and then looks at the words inside the lines that changed.
The similarity score is the share of words that stayed the same: unchanged words ÷ (unchanged words + the larger of added or removed).
Uses
- Editing: see what an editor, colleague or AI tool changed in your writing.
- Contracts and policies: spot changes between two versions of an agreement before you sign.
- Students: compare a draft with your final version, or check how closely your paraphrase follows a source.
- Developers: compare config files, API responses or code snippets line by line.
- Data: find the difference between two lists, such as email lists or product codes.
Tips
- If every line shows as changed, the texts probably use different line endings or extra spaces. Tick Ignore extra spaces.
- For copied PDFs where lines break in different places, use Words mode.
- To compare two lists regardless of order, sort them first, or remove repeats with remove duplicate lines.
- The comparison runs in your browser and nothing is uploaded, so it's safe for confidential documents.
Frequently asked questions
How do I compare two texts for differences?
Paste the original in the first box and the new version in the second. Added words are highlighted green and removed words red.
Can I compare two documents?
Yes. Copy the text from each document (Word, PDF or Google Docs) and paste it into the two boxes.
What is the difference between word and line mode?
Word mode shows changed words within sentences. Line mode marks whole changed lines, which suits code and lists.
Can it ignore case and spacing?
Yes. Tick Ignore upper/lower case or Ignore extra spaces to hide those differences.
Is my text uploaded?
No. The comparison runs in your browser, so your text never leaves your device.
Last updated October 2026 · More text tools