The appearance of GPT-5.1 Thinking on the ChatGPT website points to an imminent update from OpenAI, indicating that the previously rumored GPT-5.1 release is moving closer to reality. This model is referenced in a backend component as responsible for powering advanced reasoning processes within ChatGPT, suggesting it may be optimized for multi-step reasoning or agent-like tasks. Alongside this, rumors point to a broader GPT-5.1 lineup: Mini, Thinking, and a possible Codex-focused upgrade, each designed to fit different user needs and compute constraints.
BREAKING 🚨: GPT-5.1 confirmed as new traces of "gpt-5-1-thinking" have been spotted on ChatGPT.
— TestingCatalog News 🗞 (@testingcatalog) November 6, 2025
Gemini 3 vs GPT 5.1 soon 🥊 https://t.co/npmNxIWm6W pic.twitter.com/qAN1p655ck
These variants have reportedly been observed in internal testing environments, sometimes under obfuscated names, hinting at A/B performance testing before public launch. There is also mention of multiple models with differing “thinking budgets,” likely referring to context length, compute allocation, or reasoning depth, which would impact both consumer and enterprise offerings.
The GPT-5 models that were being tested on DesignArena are likely GPT-5-1-Thinking with different reasoning budgets
— AiBattle (@AiBattle_) November 6, 2025
There are also rumors that GPT-5-1-Thinking will have a bigger context window and reduced API pricing https://t.co/JBE7jGoZPE pic.twitter.com/6mN0npY0s0
The timing of these leaks is notable as OpenAI is likely aiming to synchronize its next wave of releases with Google’s upcoming Gemini 3 Pro launch. This fits OpenAI’s broader strategy of responding rapidly to competitive threats, especially when rival models promise strong benchmark results. Both companies are now focused on providing models with greater context windows and more nuanced problem-solving abilities.
Alright, here's the tea:
— Zaid (@zaidmukaddam) November 5, 2025
Two new snapshots of GPT-5 with lowered latency, possibly larger context window, and reduced pricing will come in the next 3-4 weeks.
One new model specifically trained for data analysis will be released early next year. https://t.co/u4dkvvmJRU
If realized, these features would benefit power users, developers, and enterprise teams who need more reliable, consistent outputs from AI systems. However, it’s still unclear whether all rumored variants will launch simultaneously or if some will remain restricted to certain tiers or API access at first. The leak was surfaced via inspection of web app components, as is often the case with early glimpses of unreleased ChatGPT features.
TestingCatalog continues to monitor for any official OpenAI statements or benchmarks that may clarify the models’ capabilities and release dates, especially as competitive pressure intensifies in the lead-up to Gemini 3 Pro’s debut.
