Text Difference Checker

The tool implements a self-contained client-side Longest Common Subsequence (LCS) dynamic programming algorithm. It compares lines from both inputs and backtracks to calculate line additions, deletions, and updates, similar to the standard Unix diff tool.

Split View displays the original and modified text side-by-side in two synchronized columns, making it easy to compare structures. Unified View displays both texts in a single merged chronological stream, with removed lines in red and added lines in green directly below.

Yes. When a line is updated (meaning a removed line and an added line are aligned next to each other), the tool runs a secondary word-level diff to pinpoint the exact words, characters, or typos that were corrected.

No. All file loading, comparisons, line-by-line diffing, and rendering happen 100% locally in your browser using JavaScript. Your confidential code or text is never transmitted or saved.

Simply copy the original code snippet and paste it into the left panel, then paste the modified code into the right panel. The tool will automatically align the code blocks and highlight exactly what lines or syntax were changed.

By default, diff tools evaluate changes line-by-line. However, our tool includes a secondary word-level diff. When a line is modified, the specific word or character that changed will be highlighted with a slightly darker background color.

Yes. You can toggle the "Ignore Whitespace" option. This will force the diff engine to ignore spaces, tabs, and empty lines, which is highly useful when comparing code that has only been reformatted or re-indented.

Currently, the tool supports manual text entry via copy and paste. For files, you simply need to open them in a text editor (like Notepad), copy all the contents (Ctrl+A, Ctrl+C), and paste them into the tool.

The standard color coding for diff tools uses Red to indicate text that was removed (deleted) from the original version, and Green to indicate text that was added in the new, modified version.

Yes! Our tool is fully responsive. While the side-by-side "Split View" works best on large desktop monitors, we highly recommend switching to the "Unified View" when comparing text on smaller mobile screens.