PDF Duplicate Review

The useful idea here is keeping two questions apart. Are these files literally identical? And do they contain the same text? A SHA-256 hash answers the first with certainty: same bytes, same file, whatever it's called. The second is fuzzier. Two PDFs can share every word and still differ in a signature, a stamp or a filled-in form field.

PDF Duplicate Review reports both, labeled separately. That matters if you're cleaning up records or preparing documents for discovery, where treating a signed and an unsigned copy as duplicates could be a real mistake. The site says outright that a text match isn't proof the pages look the same.

You select the PDFs, the extension reads their bytes and page text, groups the candidates and lets you export a CSV. The report includes skipped files and errors as well as the groups, along with the basis for each match, so there's a trail if someone asks why two files were flagged. A five-file guide on the site walks through the process.

The extension never deletes or renames anything. Deciding what to remove stays with you, which is the safer design for this kind of job. It also doesn't do OCR, so scanned pages without a text layer won't produce text matches.

The free version covers batches of up to 10 PDFs, with both checks and CSV reports and no account. Pro raises the batch to 250 for €49 once, tax included, with no recurring fee for version 1. The site says PDF content, extracted text, filenames, paths and hashes stay inside the extension, the batch is held in memory while it's open, and no PDF data goes with the license check. It comes from Kastovia Holdings LLC, which also makes PDF Reference Linker and a ClickUp focus timer.