Liner is an AI-powered search engine and research assistant designed for accurate, source-backed answers across academic and web content. It provides access to over 460 million academic papers and web sources with line-by-line citation verification, ensuring every answer can be traced back to credible references. Key features include Deep Research for generating comprehensive analysis reports, Scholar Mode for academic-only sourcing, and AI Research Agents that automate tasks like hypothesis generation, literature review, citation recommendation, and peer review feedback. Liner scored 95.3% on OpenAI's SimpleQA accuracy benchmark, making it one of the most reliable AI search tools available. Users report completing research 5.5 times faster compared to traditional methods. The platform supports mind maps and flowcharts for visualizing complex concepts, PDF and file upload for document analysis, and citation generation in multiple formats including APA, MLA, Chicago, and BibTeX. With over 13 million users across 200+ countries and a 92% Pro subscription renewal rate, Liner has established itself as the go-to research tool for students, academics, analysts, and professionals who need verified, citable information rather than generic AI-generated responses.