The best free starting point for research. Answers your question directly and cites real sources on every claim, with live web search and follow-up questions in threads. Often beats Google when you want to understand a topic with sources you can verify.
Best for: Checking whether a claim is actually true, tracing a statistic back to its original source, and researching this week of news
Limitations: Five Pro searches a day on free, and it is noticeably weak at creative or long-form writing
Best suited for: Journalists, students and analysts who have to show where an answer came from
Searches over 200 million peer-reviewed papers and shows you what the scientific literature actually says on a question, with a consensus view across studies. The free plan gives you a monthly allowance of searches. Excellent for evidence-based answers.
Best for: Checking what published studies actually conclude on a question, and finding papers that agree or disagree
Limitations: 20 searches a month goes fast during active research, and it only covers scientific literature
Best suited for: Students and clinicians who need evidence rather than a confident-sounding summary
A research assistant built for literature reviews. Finds and summarises relevant academic papers and can extract key data tables from them. The free plan limits results per search but is genuinely useful for graduate students and researchers.
Best for: Screening papers for a literature review, extracting methods and findings into a table, and finding related studies
Limitations: Five papers per search is thin for a systematic review, and monthly usage caps apply on free
Best suited for: Postgraduate researchers running structured literature reviews rather than casual searches
Upload your own documents, papers, or notes and ask questions grounded only in those sources, which keeps answers accurate. It can even turn your material into an audio overview. A free standout for understanding large documents quickly.
Best for: Asking questions across a set of uploaded papers, and generating an audio overview of dense source material
Limitations: 100 notebooks with 50 sources each, three Audio Overviews a day, and browser only with no dedicated mobile app
Best suited for: Researchers and students working across a defined set of documents rather than the open web
Upload a research paper, highlight any confusing section, and get a plain-language explanation. Ideal for students and early researchers tackling dense academic writing. Free to use with an account.
Best for: Highlighting a dense paragraph in a paper and getting it explained at your level
Limitations: Web interface only with no Zotero or reference manager integration, and explanations sometimes trade precision for clarity
Best suited for: Undergraduates and early researchers reading papers above their current level
Builds a visual graph of how papers relate to each other, so you can see the key works around a topic and find important papers you might have missed. The free plan includes a monthly number of graphs. A great citation and discovery tool.
Best for: Mapping the citation landscape around a seminal paper, and finding key work you missed
Limitations: Five graphs a month limits systematic use, and it maps citation relationships rather than paper content
Best suited for: Researchers starting in an unfamiliar field who need to find the important papers
Summarises research papers into structured bullet points and flashcards, including the methodology and findings. A browser extension works on papers you find online. Useful for processing many papers quickly for a course or assignment.
Best for: Turning a paper into a structured summary card, extracting key figures, and building a reading list fast
Limitations: The browser extension is free but the full library needs a subscription, and summary quality depends on how well structured the paper is
Best suited for: Students processing a stack of papers before a deadline rather than reading each closely
A computational knowledge engine that gives reliable answers for maths, science, and data queries, often with step-by-step working. Indispensable for STEM research and study where you need factual, computed results rather than a chatbot guess.
Best for: Solving equations with working shown, unit conversions, and plotting functions accurately
Limitations: Most queries are free but full step-by-step working needs Pro at $7.25 a month, and it is useless for open-ended questions
Best suited for: STEM students who need computation they can trust rather than a plausible guess
A free Google app that lets students photograph a question and get step-by-step explanations across many subjects. Great for quick homework research and understanding a concept from your phone.
Best for: Photographing a homework question and getting a worked explanation, across maths, science and history subjects
Limitations: Strongest at school level and weaker on advanced university content, and photo recognition misreads messy handwriting
Best suited for: Secondary school students working through homework questions on a phone after class