Best AI to summarize PDFs and long documents (free)
Upload a PDF or paste text and get key points fast — the best free AI tools to summarize documents.
Updated 2026-05-30
Key takeaways
- ChatGPT and Claude let you upload a PDF and ask for a summary, free.
- Claude handles very long documents best (large context).
- NotebookLM summarizes with citations back to the source.
The best free AI to summarize PDFs and long documents is Claude (for very long files) or ChatGPT — both let you upload a document and ask for key points. For grounded, cited summaries, Google's NotebookLM ties every point back to the source.
Claude — best for long files
Claude's large context window handles big PDFs and reports in one go, giving accurate summaries and letting you ask follow-ups.
ChatGPT — flexible
Upload a PDF to ChatGPT and request a TL;DR, bullet points or section summaries; free tier covers most documents.
NotebookLM — grounded & cited
Drop documents into NotebookLM for summaries that cite the exact source passages — best when accuracy matters.
Tools mentioned
Claude
AI assistant known for long-context writing, analysis and coding.
ChatGPT
The most widely used AI chatbot for writing, coding and research.
NotebookLM
Google's AI notebook that reasons over your own documents.
Perplexity
AI answer engine that cites its sources for every claim.
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FAQ
What is the best free AI to summarize a PDF?
Claude (best for long documents) and ChatGPT both let you upload a PDF and summarize it for free; NotebookLM adds citations.
Can AI summarize a 100-page document?
Yes — Claude's large context window is well suited to long PDFs; split very large files if you hit limits.