About Compare PDF

This tool extracts the plain text from both PDFs and runs a line-by-line diff — the same underlying approach as a code `diff` or `git diff` — rather than a visual, pixel-level comparison. That makes it well suited for catching wording changes: text that was added, removed, or reworded between two versions. It is not comparing layout, images, colors, or formatting; a page that looks different but contains the same text won't register as changed, and a paragraph that moved to a different visual location but kept its wording will typically read as "unchanged" or reordered rather than "moved."

The output is a downloadable HTML report, not a PDF — it opens directly in any browser as a two-column, line-numbered table with additions and removals color-coded and a running tally of "added / removed / unchanged" lines at the top. Comparison is capped at the first 1,500 lines per document; longer files get a visible truncation warning rather than a silent, incomplete result.

Key Features

• Line-by-line text diff — the same underlying approach as a code diff tool
• Output is an HTML report that opens in any browser, not a PDF
• Added / removed / unchanged line counts summarized at the top of the report
• Works on two PDFs with different page counts or layouts
• Comparisons over 1,500 lines per file are truncated with a clear on-screen warning