Liner

Liner is an AI search and research product built around verifiability. Answers come with line-by-line citations you can open in one click, follow-up questions to dig deeper, and mind maps for untangling complex topics. The company says its Advanced Search, which draws on carefully selected sources, scored higher than ChatGPT's advanced model and Perplexity Pro on OpenAI's SimpleQA accuracy benchmark — a vendor claim, but one that signals what Liner optimizes for.

The product is split into three agents under one subscription. Liner handles everyday search and Deep Research reports. Liner Scholar is aimed at academic work: finding and comparing papers, recommending citations, generating literature reviews, and running specialized tools such as a hypothesis generator and evaluator, research tracer, survey generator, survey simulator and peer-review assistant. Liner Write drafts emails, newsletters and reports from a topic and lets you edit and verify without leaving the window. File upload lets you summarize and query your own PDFs.

Pricing mixes daily and monthly allowances. Free users get daily credits, unlimited Advanced Search, a single small file upload per day and ads in answers. Pro and Max add monthly agent credits, larger and more frequent uploads, ad-free answers and access to major external models (ChatGPT, Gemini, Claude). Different actions cost different credits — a Deep Research request or literature review costs far more than a basic search. Team and Enterprise plans add central billing, admin controls and exclusion of team data from AI training. An API and MCP server are also offered.