Perplexity — RAG-First Search AI
The Librarian Who Searches Before Answering
6 min read
The Librarian Who Searches Before Answering
Most AI models answer from memory. Perplexity checks the library first.
Ask a regular AI a current affairs question and it might confidently answer from outdated training data. Ask Perplexity and it first searches the web, retrieves the most relevant live sources, and then generates an answer grounded in those sources — with citations. It's less a chat AI and more a research tool that synthesises the web on demand.
In Plain English
Perplexity is an AI-powered search engine that searches the web in real time before generating any answer. Unlike other AI tools, it doesn't rely on a single model — it routes your query to the best available model (GPT-5, Claude, Gemini 3, or its own Sonar model) depending on the task, while grounding every response in live web sources with citations.
The Technical Picture
Perplexity implements a search-augmented generation pipeline with intelligent model routing. Its proprietary Sonar model handles real-time retrieval. Pro queries are routed to frontier models including GPT-5 and Claude depending on task type. The 'Model Council' feature (launched February 2026) runs three models in parallel for higher-confidence answers. This multi-model architecture bypasses knowledge cutoff limitations entirely.
Real-World Examples
- Perplexity routes research queries to GPT-5 or Claude while using its Sonar model for fast search retrieval
- The Model Council feature runs three frontier models in parallel and compares their answers
- Perplexity's Deep Research compiles multi-source reports — now running on Claude Opus for Max users
Perplexity is not a wrapper around one model — it's a smart router that picks the best AI for your query, always grounded in live web search.