Free Text Diff Checker – Compare Two Texts Online
Compare two texts online and instantly find differences. Highlight added, deleted, and modified words, characters, and lines with our free Text Diff Checker.
Removed from original Added in modified
What Is a Text Diff Checker?
A text diff checker compares two pieces of text and shows exactly what changed between them. Instead of reading both versions side by side and hunting for edits, you paste the original and the modified text, and the tool highlights what was added, what was removed, and what stayed the same.
It is useful for reviewing edits to an article, checking a contract revision, comparing two versions of a document, or spotting a single changed character in a long paragraph.
How to Compare Two Texts Online
- Paste the original text into the left box and the modified text into the right box.
- Choose a comparison mode: Word diff, Character diff, or Line diff.
- Turn on Ignore case or Ignore whitespace if capitalization or spacing changes don’t matter to you.
- Click Compare texts (or press Ctrl + Enter) to see the differences.
- Switch between Side-by-side and Inline views, then copy the diff or download a TXT report.
How Does Text Diff Work?
The tool first splits each text into units: words, characters, or lines, depending on the mode you choose. It then finds the longest sequence of units the two texts share, using the Myers diff algorithm, the same family of methods behind many code review and version control tools. Units that appear only in the original are marked as removed, and units that appear only in the modified text are marked as added.
The similarity score is an estimate calculated as 2 × unchanged units ÷ (units in the original + units in the modified text). It depends on the comparison mode, so the same two texts can score differently in Word diff and Character diff.
Word Diff vs. Character Diff vs. Line Diff
| Mode | Compares | Best for |
|---|---|---|
| Word diff | Word by word | Articles, marketing copy, emails, and everyday editing |
| Character diff | Character by character | Spelling fixes, typos, URLs, and tiny changes |
| Line diff | Line by line | Code, lists, configuration files, and long documents |
Word diff is the default because it gives the most readable result for ordinary writing. Line diff also highlights the changed words inside each modified line.
Who Can Benefit from a Text Comparison Tool?
- Writers and editors reviewing revisions between drafts.
- SEO and content teams checking what changed after a page rewrite.
- Developers comparing snippets, logs, or configuration files.
- Students and researchers comparing versions of an essay or a quotation.
- Legal and business teams spotting wording changes between document versions.
Frequently Asked Questions
How do I compare two texts online?
Paste the original text in the left box and the modified text in the right box, choose a comparison mode, and click Compare texts. Added text is highlighted in green and removed text in red.
How can I find differences between two documents?
Copy the text from each document and paste it into the two boxes. Use Line diff for a structural overview, or Word diff to see exactly which words changed.
What is the difference between Word diff and Line diff?
Word diff compares the texts one word at a time, which suits articles and copy. Line diff compares one line at a time, which suits code and lists, and it still highlights the changed words inside modified lines.
Can I compare long texts?
Yes. There is no small character limit, and the comparison runs in your browser. Very long texts with many differences can take a few seconds, and Line diff is usually the fastest option for them.
Can I compare two versions of an article?
Yes. Paste the old version as the original text and the new version as the modified text. Word diff gives the most readable view of editorial changes.
Does this tool support code comparison?
You can paste code as plain text and compare it with Line diff or Character diff. The tool treats everything as text, so it doesn’t parse or syntax-highlight code.
Is my text stored or uploaded anywhere?
No. The comparison runs entirely in your browser, and your text is not sent to a server or stored by this tool.
Is this Text Diff Checker free?
Yes. It is free to use, with no sign-up required.
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