Compare two texts and see differences highlighted line by line. Shows additions, removals and unchanged lines.
What Is Text Diff Tool?
A text diff tool compares two pieces of text and highlights exactly what changed between them — additions, deletions and modifications. It works like the "track changes" feature in word processors or the diff view in version control systems like Git, but for any arbitrary text.
Seeing changes highlighted side by side makes it far faster to review edits than reading both versions manually. This is invaluable for proofreading, code review, contract comparison and any situation where you need to understand exactly what changed between two versions of a document.
How to Use This Tool
Paste the original text in the left panel.
Paste the modified text in the right panel.
Differences are highlighted instantly: green for additions, red for deletions.
Scroll through the results to review each change.
Copy the diff output for documentation or review purposes.
Tips & Best Practices
Normalise whitespace and line endings before comparing if those differences are not meaningful.
For long documents, look at the change count first to gauge how extensive the edits are.
Use this tool to verify that find-and-replace operations made only the intended changes.
When comparing code, check that the diff tool handles indentation changes the way you expect.
Common Use Cases
Reviewing editor feedback by comparing original and edited versions of an article or essay.
Comparing contract versions to identify changes in terms and conditions.
Verifying code changes before committing to version control.
Checking that automated text processing (search-replace, formatting) only made intended changes.
Frequently Asked Questions
How does the diff algorithm work?
Uses Longest Common Subsequence (LCS) to find the minimal set of changes between two texts, shown as additions and removals.