Liner

Market position

Positions itself as an accuracy-focused AI search and research agent. As of late July 2026 it ranked 30th in global AI service web traffic on Similarweb, ahead of Poe, Mistral AI and Glean, and it is described as the only South Korean AI startup featured on a16z's "Top 100 GenAI Consumer Apps" list for four consecutive editions since 2024.

Emphasis on verifiable, source-cited output at the sentence level and measured factual accuracy (95.3% on SimpleQA) rather than open-ended generation, combined with a domain-specialised agent portfolio spanning academic research, professional writing and investment research, and an academic corpus of over 500 million records.

Technology

Citation-first retrieval and answer generation over web content and academic literature, with per-sentence source attribution; access to multiple third-party frontier models (GPT-5, Gemini, Claude); an academic database of over 500 million records; multimodal inputs (documents/PDFs, images, YouTube video) and deep research workflows. The company reports a 95.3% score on OpenAI's SimpleQA factual-accuracy benchmark and says it outperformed GPT-4 in search-response generation.

Go-to-market

Product-led growth across web and mobile apps (iOS/Android) with a freemium funnel, which the company says built its global user base without heavy marketing spend; enterprise expansion via partnerships such as the HUMAIN ONE deployment, and visibility through third-party rankings and awards.

Academics, students, researchers and educators, plus knowledge workers and professionals such as consultants, content researchers, product managers, business strategists and customer success staff; enterprise and government buyers via B2B deployments.

Geography

Headquartered in Seoul, South Korea (Mapo-gu), with a San Francisco presence used for its Series C announcement and a US contact number. Users span 220 countries including the U.S., Europe, India and Southeast Asia; enterprise deployment in Saudi Arabia via HUMAIN.

History

Liner raised an angel round of approximately $0.64M, a roughly $3.2M Series A in July 2020 (KB Investment, SL Investment, Capstone Partners), a $7.07M Series B in September 2022, and a $17.3M Series B2 in October 2024. It subsequently broadened from a single consumer search product into a portfolio of agents (Liner Scholar, Liner Write, Liner Finance) and into B2B enterprise AI, culminating in a $36.1M Series C announced in August 2026.

Risks & controversies

Android user reviews report app instability (freezing, lag, a missing send button) and dissatisfaction with the constraints of the new credits system; one long-time reviewer criticised the product's shift away from its earlier web-highlighting functionality toward content recommendation. The Series C announcement itself notes a broader market correction and tightening diligence across the AI industry. The app's Play Store listing indicates sharing of location and personal data with third parties.