Diff Viewer Online
Fast, accurate and free online diff viewer online tool running directly in your browser.
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1Enter data
Enter content, paste text or load a file from disk. -
2Click the button
The tool will immediately process your data in the browser. -
3Get the result
Copy the finished text or save the file to your device.
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Other tools you may find usefulText comparator (diff online)
The tool allows you to quickly compare two versions of text or source code directly in the browser. Just paste the original and the changed version, and the LCS algorithm will immediately indicate the differences - line by line, with color-coded additions and deletions.
What is
Useful for? An online text comparator will be useful wherever you need to quickly determine what has changed between two versions of a document, configuration or code. Developers use the code review tool when they do not have access to a version control system, and editors use it to detect changes between versions of articles. The tool supports any UTF-8 text: JSON, YAML, XML, Markdown, HTML, CSS, Bash scripts and plain text files. The whitespace ignore option eliminates false positives with various formatting, and the case ignore option allows you to focus on substantive content changes.
How to use
1. Paste the original text into the Original Text box (A) on the left.
2. Paste the changed version into the Changed Text box (B).
3. Optionally, enable Ignore Whitespace or Ignore Case.
4. Click Compare - the result will appear on the right.
5. Green lines are additions (+), red lines are deletions (−), gray lines are unchanged lines. The statistics bar shows the number of lines added, deleted and untouched. The Copy (plain) button exports diff in text format to the clipboard.
Applications in working with code
During code review, the comparator allows you to quickly view a changed configuration file or script fragment without having to run git diff. It is also useful when comparing two versions of API documentation, environment files (.env) or email templates. Files up to 5,000 characters per page are supported.
Comparing text documents
Editors and copywriters can paste two versions of an article and immediately see which paragraphs have been changed, added or deleted. The whitespace ignore feature ensures that minor formatting differences don't clutter your results. The diff result can be copied in plain format and pasted into notebook or e-mail as a clear summary of changes.
FAQ
Does the tool save pasted texts?
No. The comparison is performed during the request and is not saved anywhere. The field contents are passed only for the calculation of differences and immediately deleted.
What is the text length limit?
Each of the two fields accepts up to 5,000 characters. For larger files, we recommend using command line tools (diff, git diff) or dedicated editors that support large files.
What is the difference between Ignore Whitespace and Ignore Case?
Ignore whitespace causes multiple spaces and leading/trailing spaces to be treated as identical - useful when comparing code after autoformatting. Ignore Case treats Lorem and Lorem as the same text - useful when comparing content when the change in case is not important.
How does the comparison algorithm work?
The tool uses the LCS (Longest Common Subsequence) algorithm operating at the line level. Determines the longest common string unchanged and marks the remaining lines as added or deleted. This is the same method used by the classic diff command on Unix/Linux systems.
Can I compare code in a specific programming language?
Yes – the tool supports any text, including PHP, Python, JavaScript, SQL, JSON, YAML, XML, Bash and more. Coloring the diff results indicates lines added (green) and deleted (red), regardless of the programming language.