AnswerThis

AnswerThis is an AI research assistant that searches more than 300 million papers, clinical trials and uploaded PDFs and returns answers with line-by-line citations back to the source. Founded in 2024 and backed by Y Combinator, it covers the stretch of the workflow between a research question and a written draft: finding the literature, screening it, extracting what each paper actually says, and drafting text that stays attached to its sources.
Why it matters
The search-and-screen stage of a literature review takes weeks by hand and is the bottleneck at the start of most projects, AnswerThis compresses it to minutes and leaves the judgement to the researcher.
Claims are checked against a retrieved source before they are shown and unsupported statements are dropped rather than guessed at, which is the failure mode that makes general-purpose chatbots unusable for citation work.
A research gap finder surfaces gaps that published authors have explicitly stated, instead of asking the user to infer them from the reading.
Systematic review tooling follows PRISMA and Cochrane conventions, so the output is auditable rather than only readable.
Key features & advantages
Cited question answering: ask a research question and get an answer assembled from indexed papers, trials and PDFs, with each sentence carrying its own citation.
Library: import your own PDFs and run grounded question answering over the collection, with export in over 2,000 citation styles.
Canvas and AI Writer: a drafting environment that pulls verified sources into the text as it is written, rather than citations being added afterwards.
Systematic review: PRISMA and Cochrane-aligned screening with extraction into structured tables for regulatory-facing reviews.
Research gap finder: scans the retrieved literature for limitations and future-work statements and collects them into a list of open questions.
Collaboration: shared libraries and workspaces for labs and teams, with audit trails on the enterprise tier.
Limitations & things to watch
Verification confirms that a cited source exists and supports the sentence, not that the source is any good, study quality still has to be judged by the reader.
Coverage is bounded by the indexed corpora, paywalled, non-indexed and non-English work can be missed without the gap being visible in the output.
The free tier is capped, frontier models and the systematic review workflow sit behind the paid plans.
Generated reviews compress the caveats the original authors were careful about, they are a starting point for reading rather than a substitute for it.