Whether you are reviewing code changes, comparing contract versions, checking edited documents, or validating data transformations — knowing exactly what changed between two pieces of text is essential. Our free Text Diff Checker highlights every addition, deletion, and unchanged line in seconds with a clean side-by-side or unified view.
What Is a Text Diff Tool?
A diff tool compares two versions of text and shows exactly what changed. It uses the Longest Common Subsequence (LCS) algorithm — the same algorithm used by Git, GitHub, and most version control systems — to find the minimum set of changes that transforms one text into the other.
How to Use the Text Diff Checker
- Paste your original text in the left box
- Paste your modified or updated text in the right box
- Click Compare Texts to run the diff
- Green lines are additions, red lines are deletions, gray lines are unchanged
- Toggle between Split View and Unified View as preferred
Split View vs Unified View
Split View shows the original and modified text side by side with differences highlighted on the same lines. This is ideal for reviewing small changes in context. Unified View shows all lines in a single column with added lines marked with a plus sign and removed lines marked with a minus sign — similar to what you see in Git diffs.
Common Use Cases
- Code review — Compare two versions of a function or script before and after edits
- Document editing — See what a proofreader or editor changed in your content
- Contract review — Spot every clause change between two versions of a legal document
- Data validation — Check if two CSV or JSON outputs match or differ
- Configuration management — Diff two config files to find setting differences
- Academic work — Compare assignment drafts against the final submission
Is the Text Diff Tool Safe to Use?
Yes — completely. The diff runs entirely in your browser using JavaScript. Your text is never sent to any server, never logged, and never stored. You can paste confidential contracts, private code, or sensitive documents without any privacy risk. Disconnect from the internet and the tool works identically — because there are no network calls.
Compare your texts now at owndevz.com/text-diff-checker — free, instant, and private.
