Best Long-Context AI Models
Models with the largest context windows, for long documents, whole codebases and multi-file agents. Ranked by context size, all on one API on thalam.
- 1AIGPT-6 Astra$10.00 / 1M · 1M context · Medium
OpenAI's GPT-6 generation. Frontier reasoning with a 1M-token context, image input, and adjustable reasoning effort.
- 2AIGPT-5.6 Sol$5.00 / 1M · 1M context · Medium
The top tier of OpenAI's GPT-5.6 generation. Frontier reasoning, coding, and agentic work with a 1M-token context and image input.
- 3AIGPT-5.6 Terra$2.00 / 1M · 1M context · Medium
The balanced tier of OpenAI's GPT-5.6 generation. Same 1M-token context and image input, tuned for everyday production work.
- 4AIGPT-5.6 Luna$0.20 / 1M · 1M context · Fast
The fast, high-volume tier of OpenAI's GPT-5.6 generation. Keeps the 1M-token context and image input at the lowest rate in the family.
- 5KMKimi K3$3.00 / 1M · 1M context · Medium
Moonshot's new flagship generation. A 1M-token context and the strongest measured reasoning in our catalog.
- 6DSDeepSeek V4.1 Flash$0.300 / 1M · 1M context · Fast
DeepSeek's V4.1 Flash. A 1M-token context and a 384K output ceiling, with image input, tool calling and reasoning built in.
One OpenAI-compatible endpoint for every model above. Pay per token, no subscription, credits never expire.
FAQ
Which AI model has the biggest context window?
Several frontier models now offer a 1M-token context window, enough for very long documents or an entire codebase in a single prompt. thalam lists the exact context window on every model page.
Does a bigger context window cost more?
You pay per token, so a longer prompt costs more only because it contains more tokens, the window size itself has no separate fee on thalam. Retrieval (RAG) is still often cheaper than stuffing everything into context.