AI research and search suite spanning Liner, Liner Scholar and Liner Write, with Deep Research, file analysis and access to major AI models on paid tiers.
Liner has evolved from a highlighting/search utility into a broader research-AI suite spanning the main Liner search product, Liner Scholar and Liner Write. Current plans include unlimited Advanced Search and Scholar Mode, line-by-line citations, Deep Research, file analysis and access to major external AI models on paid tiers. The suite is available on web, mobile and browser-extension surfaces. 1
Liner Scholar is the academic surface, while the broader product supports everyday cited search and document work. Liner also exposes a developer platform: Web Search and Scholar Search APIs, visualization endpoints, and Quick Answer, Search, Deep Research and Visual Answer agent APIs. This corrects older catalog descriptions that treated Liner as having no public API. 2
The product is mature in distribution but its strongest accuracy claims remain vendor-reported. Liner cites a 95.3 SimpleQA score and recent company materials report more than 14 million registered users; those signals support scale and product maturity but should not be treated as independent quality benchmarks. 3
Free costs $0 and includes unlimited Advanced Search, Scholar Mode and line-by-line citations, limited research-assistant use, one 25MB file upload per day and ad-supported answers. Pro is $17.99 monthly or $14.99 per month billed annually, with 1,000 agent credits, 20 daily file uploads up to 100MB and access to major AI models. Max is $35.99 monthly or $29.99 billed annually, with 2,500 credits and much higher file limits. Team is $26.99 per seat/month and Enterprise is custom. 1
The developer API is separate usage-based pricing. Web Search is $1 per 1,000 requests and Scholar Search is $0.30 per 1,000; agent endpoints range from $3 per 1,000 Quick Answer calls to $200 per 1,000 Deep Research calls. This is unusually transparent, but it means organizations using both the consumer suite and APIs need to model two distinct usage systems. 2
The current App Store listing shows Liner at 3.9/5 from 96 ratings in the UK snapshot, while Google Play shows about 4.0/5 from 4.54K reviews and more than 500K downloads. These are exact-product signals but only partial evidence for the full web/Scholar/API suite. 45
Trustpilot requires careful identity handling. The current liner.com profile contains unrelated reviews and cannot be treated as Liner AI evidence. The legacy getliner.com profile has nine reviews, several clearly about Liner AI and recurring billing, cancellation and support complaints, including a 2026 complaint about overcharging and unresponsive support. These are used qualitatively only; the legacy sample is small. 6
Liner's July 2026 privacy policy says user content can be sampled to improve internally developed models unless the user disables history and learning. It also states that Google, OpenAI and Anthropic may process content for AI features with provider retention up to 30 days. Users can request deletion, and account data is generally kept until withdrawal with a short post-withdrawal recovery period. 7
Security documentation is comparatively detailed. Liner says it maintains SOC 2 Type I and II and ISO 27001:2022 certifications, supports data controls and deletion, and evaluates institutional security requirements such as HECVAT. Enterprise/API terms also warn that generated factual assertions may be false or incomplete and require independent verification. 89
Liner is best for students, academics, analysts and knowledge workers who want one environment for cited web search, scholarly discovery, deep research, files and access to multiple major models. The developer APIs broaden the fit to teams building search or research features into their own applications.
It is less suitable for users who want a single simple subscription with no credit mechanics, organizations uncomfortable with opt-out rather than default-off consumer model-improvement use, or buyers that require extensive independent benchmarking before deployment.
broad research suite across Liner, Scholar and Write; unlimited Advanced Search and Scholar Mode even on Free; line-by-line citations and Deep Research; major-model access on paid plans; public Web, Scholar and agent APIs with transparent usage pricing; large current Android review base and cross-platform availability; SOC 2 Type I/II and ISO 27001:2022 claims with dedicated security documentation.
independent comparative evidence remains limited; mobile ratings are good but not category-leading; legacy product reviews repeatedly raise billing/cancellation/support concerns; consumer content may be sampled for model improvement unless the user opts out; multiple credit and API billing systems add complexity; full-suite capabilities are materially broader than mobile evidence, limiting direct rating transfer.
A preview from the separate AiToolMap video library. These videos complement the written review; they are not part of the rating.
Liner
Official Liner tutorial embedded in its research guide, showing AI Search for credible sources, summaries and citation generation.
WATCH ON YOUTUBE ↗Liner
Official Liner Copilot tutorial embedded in the product guide, covering article, paper and YouTube summarization plus contextual Q&A.
WATCH ON YOUTUBE ↗Liner
Official Liner Scholar Mode walkthrough covering scholarly-source search, summaries and line-by-line citations.
WATCH ON YOUTUBE ↗Products matched by shared tasks, audience, workflow, product type and capabilities.