Text Diff Checker
Paste two blocks of text and see a visual highlighted diff showing additions, deletions, and changes between them — useful for comparing document versions, code snippets, and more. 100% in your browser.
Quick answer
Paste two blocks of text below and click Compare. Added lines appear in green, removed lines in red, and unchanged lines in gray. All comparison happens in your browser \u2014 nothing is sent to a server.
How to compare text
Follow these three quick steps to find differences between two texts.
Paste your texts
Paste the original text in the left box and the modified text in the right box.
See the visual diff
Lines are highlighted: green for additions, red for deletions, gray for unchanged content.
Review or copy
Scroll through the diff to review changes, or copy individual lines to your clipboard.
Visual line-by-line comparison
Visual line-by-line diff highlighting changes
Visual line-by-line diff highlighting changes
Added lines shown in green, removed in red, unchanged in gray
Added lines shown in green, removed in red, unchanged in gray
Longest Common Subsequence (LCS) algorithm for minimal edits
Longest Common Subsequence (LCS) algorithm for minimal edits
Copy individual changed lines or the full diff
Copy individual changed lines or the full diff
100% private — nothing leaves your browser
100% private — nothing leaves your browser
No sign-up, no limits
No sign-up, no limits
Works with prose, code, configs, and any text
Works with prose, code, configs, and any text
Works with any text
- Plain text
- Markdown
- Code
- JSON
- CSV
- Config files
Privacy and security
What this tool does not do
- This is a line-level diff — character-level changes within a line are not shown.
- No file upload support — paste text only.
- For large, binary, or very long-line files, consider a dedicated diff tool.
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Frequently asked questions
Is this tool free?
Yes — completely free, no sign-up required. All comparisons run in your browser and nothing is sent to a server.
What diff algorithm do you use?
We use a line-based Longest Common Subsequence (LCS) algorithm to find the minimal set of edits. It highlights added, deleted, and changed lines between the two texts.
Do you store my text?
No. All comparison happens locally in your browser. Your text never leaves your device.
Can I compare large documents?
There is no hard limit — everything runs in your browser. Very large texts may slow things down, but for normal documents it is instant.
Does it work with code files?
Yes — the diff is line-based, so it works equally well with prose, code, configuration files, or any text format.
Is this a word-level or line-level diff?
This is a line-level diff — it compares whole lines. For character-level diffs within a line, we recommend a dedicated code diff tool.