AI reference

Clear AI definitions and model data you can check.

A glossary written for practitioners, research summaries, and language models compared on price, limits and capabilities, with a source and a date next to every number.

255glossary terms
134articles
65models priced
next-token-prediction.py

Glossary

255 terms · A–Z

Definitions first, then how it works, worked examples, formulas and code.

LLM API pricing

65 models · 5 vendors

Per-token prices from each vendor's own page, with cache, batch and long-context rates.

Models

10 model cards · 9 comparisons

Context windows, limits and capabilities, with the source behind each value.

Tools

Token counter · cost calculator

Count the tokens in your prompt, then see what a month of traffic costs on every model.

LLM changelog

27 changes · last Oct 14, 2026

Model launches, price changes and retirements, each linked to the vendor's notice.

News and research

134 articles

Pricing news, research summaries and applied machine learning explainers.

Paying for a chat app rather than the API? See chatbot subscription plans.

Fresh in the reference

Recently updated in the glossary

Latest articles

All 134 articles
Latest
AI Education

Types of AI: The 3, 4 and 7 Types Explained, and Which Ones Actually Matter

There is no single official list of the types of AI . Popular pages give you three, four, seven or even fifteen because they sort artificial intelligence along different axes: what a system can do (capability), how it behaves while running…