OpenAI raises GPT-6.1 Sol default context to 500k in Codex and Work

On October 12, 2026, OpenAI raised the default context length of GPT-6.1 Sol in Codex and ChatGPT Work from 272k to 500k. According to TestingCatalog, the previous default was 272k, and OpenAI also plans to increase this default value further in the future, meaning developers can handle longer code and documents without extra configuration.

Later that day, IT之家 reported that Thibault Sottiaux (Tibo) of OpenAI announced the change, saying the default context length had been lifted from 272k to 500k, an increase of about 80%. He said the adjustment significantly reduces how often context compression is triggered and makes it easier to handle tasks that require retaining large amounts of context and complex details over long stretches. The value was thoroughly tested and represents the sweet spot between experience and performance for the vast majority of users. GPT-6.1 Sol still supports a maximum context length of 1M, and users can manually raise or lower the setting. Alongside the change, OpenAI will not charge long-context fees for GPT-6.1 Sol when usage is deducted from a subscription.

The new default is now in effect. As for whether the default will be raised again, the materials only mention that OpenAI has such a plan, without giving a specific timeline.