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ChatPDF vs Knowbase

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Knowbase publishes a starting price ($19); ChatPDF does not. Both have a free tier. Both ship a public API.

ChatPDFAsk questions about PDFs, documents and videosKnowbaseUpload documents, audio and video into one library, then ask questions across all of it

Side by side

FactChatPDFKnowbase
CategoryPDF ToolsChat with Documents & PDF
Pricing modelFreemiumFreemium
Starts at—$19 month
Public APIYesYes
PlatformsWeb, macOS, APIWeb, API
CompanyChatPDF GmbH—
Launched2023—
Last verifiedSep 6, 2026Sep 6, 2026

What our research says

ChatPDF

The quickest way to interrogate one long PDF without building retrieval yourself, and the page-level citations are what keep it honest. But ChatGPT and Claude now read PDFs natively, so ChatPDF only earns its subscription if you need those citations, the multi-file view, or the API.

Pros

  • answers cite specific pages, so you can check them instead of trusting them
  • handles Word, PowerPoint, Markdown and text files, not only PDF
  • REST API supports streaming and multi-turn conversations
  • free tier works with no account and no card

Cons

  • two documents a day on free runs out fast during real research
  • Plus pricing is not published anywhere on the site
  • no team plan, SSO or shared document library
  • hard per-file limit of 2,000 pages or 32 MB

Knowbase

Stronger than the usual chat-with-PDF tool because audio and video are first-class: transcription with speaker labels means meeting recordings join the same searchable pool as the documents. The limits are storage and query counts, and they bite early - 500 queries a month is a fortnight of real use.

Pros

  • Transcribes audio and video with speaker identification, then makes it searchable alongside documents
  • Queries either a single file or the whole library in one go
  • Connectors for Google Drive, Notion and Dropbox rather than upload-only
  • Shareable links and an embeddable chatbot widget, plus a documented API

Cons

  • Query caps are low - 500 a month on the $19 tier - and count against everyone in a shared workspace
  • No company name, address or jurisdiction is published on the site or in the terms PDF
  • Storage on the entry tier is 2 GB, which a handful of video files will exhaust

Which one fits

Choose ChatPDF if you need

  • students and researchers pulling verifiable quotes out of long papers
  • checking claims inside a contract or report you did not write
  • developers wanting a hosted PDF-Q&A endpoint instead of rolling their own RAG stack

Choose Knowbase if you need

  • Anyone whose reference material is a mix of documents, recordings and video
  • Small teams wanting an embeddable support chatbot fed from their own files
  • Researchers who need answers with citations back to the source file

More comparisons

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