Perplexity
AI-powered answer engine — real-time web search + LLM synthesis with inline citations. Strong research workflow companion.
freemium
ChatGPT
Chatbotpaid
OpenAI's flagship conversational AI. Strong general reasoning, code, and document analysis. GPT-4o multimodal with vision and voice modes.
Cal's take on ChatGPT
Cal hasn't reviewed this tool yet.
Pricing
- Model
- paid
Features detail
Full feature breakdown for ChatGPT coming Phase 1.5 — Cal-curated feature inventory pulled from vendor docs + community signal.