Document Compare
Compare two Word (.docx) documents side by side and highlight differences. Upload original and modified files to see added, deleted, and changed paragraphs instantly. 100% browser-based, privacy first. Free, no sign-up required.
Original Document
Drop .docx here or click to browse
Modified Document
Drop .docx here or click to browse
Frequently Asked Questions
How does the Document Compare tool work?
When you upload two .docx files, we extract the text from each document's XML (paragraph by paragraph) in your browser. We then use a Longest Common Subsequence (LCS) algorithm to align the paragraphs and identify which ones were added, removed, or modified. For modified paragraphs, we also perform word-level diffing to highlight the exact changes.
What types of changes are detected?
The tool detects four types of changes: Added (new paragraphs in the modified file), Removed (paragraphs deleted from the original), Modified (paragraphs that exist in both but have different text โ with word-level highlights), and Unchanged (identical paragraphs in both files).
Does it compare formatting, images, or tables?
This tool compares text content only. It does not detect formatting changes (font, color, size), image additions/removals, or table structure modifications. The comparison is based on the text content of each paragraph in the document.
How is the comparison displayed?
The results are shown in a side-by-side view: the original document on the left and the modified document on the right. Added paragraphs appear only on the right (highlighted green), removed paragraphs appear only on the left (highlighted red), and modified paragraphs show on both sides with word-level changes highlighted.
Is it safe to upload my documents?
Yes! Both files are processed entirely in your browser using JavaScript. They are never uploaded to any server. All parsing, comparison, and rendering happen locally on your device, ensuring 100% privacy.
Can I compare .doc files?
No, only .docx files (Word 2007 and later) are supported. The older .doc format uses a binary structure that can't be parsed in the browser. Convert your .doc files to .docx first using Word or Google Docs.
Is there a limit on file size?
There is no artificial limit, but very large documents with thousands of paragraphs may take a few seconds to process. The comparison is performed entirely in your browser, so performance depends on your device's memory and CPU.
Is this tool free?
Yes, completely free with no sign-up required. All processing happens in your browser, so there are no server costs.