OpenAI raises GPT 6.1 Sol's default context in Codex and Work to 500K tokens, up from 272K
Day 7/ We have increased default context length for GPT-6.1 Sol to 500k when used through Codex & Work, up from 272k or an ~ 80% increase. We will go higher in the future, but it helps reduce occurrence of compactions and with tasks that require keeping a lot of context and nuance over periods of time. It was carefully tested and is the new sweet spot for most of our users. You can still override it if you want to be higher our lower, with maximum context length of GPT-6.1 Sol of 1M.
Context
A bigger default context window means Codex agents compact their memory less often on long tasks, a practical upgrade for developers running long coding sessions.
GPT 6.1 Sol is OpenAI's model for long running work in ChatGPT Work and Codex, and is the default model in the Codex CLI. OpenAI's developer docs list a context window of 1,050,000 tokens for the model. This change is Day 7 of the 28 day series of daily improvements or usage resets that Tibo, who runs Codex, launched on October 4.
Deep dive
On October 11, Tibo posted Day 7 of OpenAI's 28 day series: the default context length for GPT 6.1 Sol in Codex and ChatGPT Work has been raised to 500,000 tokens, up from 272,000, which he described as an increase of about 80 percent.
Tibo said OpenAI will go higher in the future, but that the new default helps reduce how often compactions happen and helps with tasks that require keeping a lot of context and nuance over time. He said the setting was carefully tested and is the new sweet spot for most users, and that users can still override it, up to the model's maximum of 1 million tokens.
Compaction is when an agent summarizes earlier parts of a long session to stay within its context limit, which can cause it to lose details. A larger default lets longer coding sessions run before that happens, though bigger contexts generally use more of a user's allowance per request.
OpenAI's developer docs list GPT 6.1 Sol with a 1,050,000 token context window and up to 128,000 output tokens. OpenAI's launch post says the model is available to Plus, Pro, Business, Enterprise and Edu users in ChatGPT Work and Codex.
In a follow up post, Tibo added that with this change OpenAI is not charging long context fees for GPT 6.1 Sol when usage is drawn from a subscription.
What to expect next
Watch for the further increases Tibo promised, and whether OpenAI explains how larger default contexts affect usage limits, which were the subject of his Pro user poll the same day.
Also watch what the remaining days of the 28 day series bring, and whether rivals such as Anthropic and Google respond with larger default context windows in their own coding agents.