Liner

AI search engine that answers with inline citations.

Hybrid search engine that returns synthesized answers with inline citations rather than a list of links. Ships a consumer product and the Sonar API for adding cited search to your own apps and agents.

AI search over peer-reviewed research papers, with inline citations.

An academic search engine that runs natural-language questions against a corpus of more than 200 million peer-reviewed papers and synthesizes the findings with inline citations. Its Consensus Meter aggregates how much the studies agree or disagree, and a copilot helps draft literature reviews. Aimed at researchers, students, and clinicians.

AI research assistant: search, read, and review the literature.

AI workspace for academics that searches a corpus of 280M+ papers, runs literature reviews, and answers questions over PDFs with citations. Adds writing aids like a paraphraser and citation generator, plus an agentic 'Deep Review' literature search introduced in 2025. Free Basic tier with paid upgrades.

AI research assistant for literature review and evidence synthesis.

Searches, summarizes, and extracts structured data across 125M+ academic papers, with sentence-level citations. Goes beyond chat-over-papers with a guided systematic-review workflow covering search, screening, extraction, and report synthesis. A free Basic plan offers unlimited search and summaries; paid tiers add data-extraction volume and the review pipeline.