Tool & Platform
Beginner
Perplexity · AI Learning & Research
An AI-native search engine whose answers cite sources — handy for quickly verifying questions that come up while studying.
Tool & Platform
Beginner
★ Featured
Google · AI Learning & Research
Google's AI note and research tool — upload PDFs, web pages and videos to ask questions, generate summaries, flashcards and podcasts, with cited answers. Generous free tier; our most recommended study aid.
Tool & Platform
Beginner
沉浸式翻译 · AI Learning & Research
A bilingual side-by-side browser translation extension — the tool for reading English docs, papers and subtitles. Core features free; the standard for accessing first-hand English material.
Tool & Platform
Beginner
ChatDOC · AI Learning & Research
A document Q&A tool — upload PDF/Word, ask questions and jump to source paragraphs. Good for papers and contracts. Free tier has quota.
Tool & Platform
Beginner
Felo · AI Learning & Research
An AI search engine that turns results into cited reports, with multilingual search. Free tier is daily-limited.