AI tools to summarize documents
Tools that solve this problem, compared honestly.
ChatGPT
8.9General-purpose AI assistant for writing, analysis and everyday tasks.
Verdict: The safest default assistant: broadest feature set and ecosystem, excellent for general work. Specialists beat it in narrow lanes — research with citations, very long documents — but as a first AI tool it is hard to argue against.
Claude
8.8AI assistant known for long documents, careful writing and coding.
Verdict: The strongest choice for long documents, careful writing and agentic coding. Writing quality and instruction-following are class-leading; the ecosystem of third-party plugins is smaller than ChatGPT's.
Ask questions of a PDF and get answers with page references.
Paraphrasing, grammar and citation tools built for students.
Analyse spreadsheets and build charts by asking questions.
Meeting transcription with CRM sync and conversation analytics.
NotebookLM
8.5Turn your own documents into a grounded research assistant.
Verdict: The most trustworthy research assistant for working with your own material — source-grounding with passage-level citations is exactly how AI research should work. It only knows what you give it, which is both its limit and its point.
Gemini
8.4Google's AI assistant, woven through Search, Gmail and Workspace.
Verdict: Unbeatable if your work already lives in Gmail, Docs and Drive — the integration is the product, and the free tier is the most generous of the major assistants. As a standalone chat experience it trails its rivals in polish.
Perplexity
8.3AI answer engine that cites its sources.
Verdict: The best tool for sourced, verifiable answers. For research and fact-finding it beats general assistants; for long-form writing or coding it isn't trying to compete.