Top Free Reasoning Long-Context AI Models

The best free reasoning long-context AI models right now, ranked by the Epoch Capabilities Index when one is published, then by launch date. 3 models match. These are models you can use at no cost, either through a free tier or because they are priced at zero, and models that think step by step before answering, and models with a context window of 1 million tokens or more, enough for several books at once.