Remove Duplicate PDF Pages
Detect and delete repeated pages using visual hashing
About this tool
Remove Duplicate PDF Pages compares every page using perceptual hashing (aHash and dHash) to catch pages that look the same even when they are not byte-identical. This handles common cases such as scanning the same sheet twice, importing the same cover page into multiple merged files, or copies created by a faulty batch process. A similarity threshold slider lets you tune how strict the match is, and a thumbnail grid shows which pages are flagged as duplicates of an earlier page so you can confirm before deleting. The first occurrence of each group is kept and the rest are removed, with the original order preserved. All processing is local — your PDF is never uploaded.
Frequently Asked Questions
How does it detect duplicate pages?
It renders each page to a thumbnail and computes perceptual hashes (aHash and dHash). Pages whose hash distance is below the similarity threshold are treated as duplicates of an earlier page.
Does it only find exact copies?
No. Perceptual hashing catches near-duplicates too, such as the same page scanned twice with minor shifts, or pages that look identical despite tiny rendering differences.
Which page is kept when duplicates are found?
The first occurrence in document order is always kept, and later duplicates are flagged for removal. You can uncheck any page before exporting.
What does the similarity threshold do?
It sets how close two pages must be to count as duplicates. A lower value is stricter (only near-exact matches), a higher value flags pages that are broadly similar.
Is my PDF uploaded anywhere?
No. Hashing, comparison, and export all run locally in your browser. Your document never leaves your device.
How does it handle large PDFs?
For documents up to 80 pages it can compare all pairs; for speed it can use a sliding window around each page. An option lets you switch between full comparison and windowed mode.
Will it remove pages with the same text but different layouts?
No. Perceptual hashing is based on visual appearance, so pages with the same text but different layout are usually not flagged as duplicates.
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