[suggestion] Search for similar documents (possible duplicates)

[Jensen Head]

I ask you to consider adding a tool to PDF-Tools to identify possible duplicate PDF files.

This is one of the tasks that is very difficult to automate. Especially when the document count is in the hundreds of thousands. You have to visually compare the previews of the first pages of documents when sorting by file size, when sorting by number of pages, compare page sizes, visually compare the fonts used, search for documents by the exact match of an arbitrary phrase from the text, and then compare them in pairs in PDF-XChange Editor or FineReader Document Compare… This is a long multi-stage process, and I don't know anything for it that resembles AllDup:
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AllDupPortable (2025-04-25 09-58-36).png

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AllDupPortable (2025-04-25 09-58-57).png

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AllDupPortable (2025-04-25 09-59-14).png

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AllDupPortable (2025-04-25 09-59-40).png

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AllDupPortable (2025-04-25 09-59-55).png

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Thus, having a set of criteria for comparison, the weight of each of them, and at the output I would like to see a list of groups of similar documents from among those processed, indicating the conditional percentage of coincidence, taking into account the settings specified in the first step. For comparison, I suggest using the parameters listed above, supplementing them with a comparison of metadata, including document creation and modification dates, Titles and language, presence of attachments, and number of text characters.

Upd. PDF-XChange Editor 10.8.4, build 409 — the feature has not been added yet.

[Stefan - PDF-XChange]

Hello Jensen Head,

I will pass that suggestin for consideration, however as you said - it is quite a tricky feature to implement, so even if this is approved - it might not be an easy or immediate solution!

I will keep you updated with any news from the dev team.

Kind regards,
Stefan