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