Diff Checker — Find Every Difference Between Two Texts Instantly
The Get-Tools Diff Checker is a free, browser-based text comparison utility designed for developers, writers, editors, translators, and anyone who needs to spot differences between two versions of a document. Simply paste the original and modified texts into the two input panels, click Compare, and see every addition, deletion, and modification highlighted with intuitive color coding. No sign-up, no installation, no file uploads required.
Three Powerful Display Modes
Split View (Side by Side)
The split view displays the original text on the left and the modified text on the right, aligning corresponding lines so you can scan changes at a glance. Added lines appear in green and removed lines in red, with empty placeholder rows inserted to keep the two panels vertically synchronized. This mode is ideal for reviewing code changes, contract revisions, or any scenario where seeing both versions simultaneously helps comprehension.
Unified View
The unified view merges all lines into a single column, prefixing added lines with a plus sign and removed lines with a minus sign, following the widely adopted unified diff format used by Git and other version-control systems. This compact representation is perfect for sharing comparison results with teammates, embedding them in code review reports, or pasting them into issue trackers.
Char by Char
The character-level comparison mode goes deeper than line-level diffing by highlighting every individual character that was added or removed within a modified line. If a single word or even a single letter changed in a long line, it will be immediately visible without reading the entire line. This mode is indispensable for reviewing translation files, verifying data entry accuracy, or catching subtle typos that line-level tools would miss.
Key Features
- Color-coded highlights: Green for additions, red for deletions, with inline character-level markers for pinpoint accuracy
- Line numbers: Every line is numbered so you can reference exact positions during team reviews
- Real-time statistics: Line and character counts update as you type, and the result header shows totals for added and removed lines
- Copy and download: Export the unified diff to your clipboard with one click or download it as a plain-text file for archiving
- Swap button: Instantly swap the contents of the two panels to reverse the comparison direction
- Sample loader: Load a built-in code example to see how the tool works before pasting your own content
Practical Use Cases
Software Development
Developers use this tool to compare two versions of a source file before and after editing, verify that branch merges completed correctly, or quickly inspect differences when a Git GUI is unavailable. It supports any programming language since it works with plain text.
Legal Documents and Contracts
When you receive a revised contract or agreement, paste both versions here to catch every change, no matter how small. This ensures that no clause modifications slip through unnoticed during negotiation rounds.
Translation and Localization
Translators use this tool to compare two versions of a translation file such as JSON, PO, or XLIFF to confirm that all keys are translated and the file structure remains intact. It is also helpful for comparing a translated text before and after proofreading.
Writing and Editing
Writers and editors compare successive drafts of articles, research papers, and reports. The tool makes it easy to track what was deleted, added, or rephrased between each revision cycle.
Privacy and Security
The Diff Checker runs entirely inside your browser. No text is sent to any external server, stored in a database, or transmitted over the network. This makes the tool completely safe for sensitive, proprietary, or confidential content. The moment you close the page or click Clear, all data is gone permanently.
Fast Performance with No Limits
The tool uses an optimized LCS (Longest Common Subsequence) algorithm implemented in pure JavaScript with no external libraries. You can compare texts containing thousands of lines at high speed. There are no limits on the number of comparisons or the length of the input. Use it as often as you need, whenever you need it.