Question: I'm looking for a way to automatically summarize PDF files and documents into shorter, more digestible versions.

ChatPDF is a good option, with an AI information retrieval system designed to help you understand PDFs better. It can handle multi-file chats, so you can create folders of files and have a single conversation with a group of PDFs. The system can handle PDFs in any language and can cite sources, which makes it good for students, researchers and professionals who want to quickly get answers out of documents.

Another option is Coral AI, which lets you quickly extract information from PDFs in more than 90 languages. It can summarize documents, answer questions with citations to the relevant pages and translate text into multiple languages. Coral AI also can generate study guides and can search without keywords, so it's good for a variety of documents.

If you want a more powerful service, ChatPDF offers more advanced features like the ability to upload hundreds of PDF files, ask natural language questions and generate text. The service offers multiple pricing tiers, so you can pick the plan that's right for you. It also prioritizes data security with GDPR-compliant storage and regular security audits.