OpenAI traces point to a GPT-5.1 “Thinking” variant inside ChatGPT
Evidence discovered in ChatGPT’s backend points to an imminent update from OpenAI centered on a GPT-5.1 Thinking model. The traces suggest the new variant is being exercised for more advanced reasoning workflows, possibly optimized for multi-step reasoning or agent-like tasks. Alongside that build, leaks indicate a broader GPT-5.1 family under internal testing, including a potential Mini edition and a Codex-focused upgrade for coding workloads.
What the leaks imply about capabilities
Internal testing traces and obfuscated model names point to A/B experiments across several axes. Key technical points emerging from the leaks:
- Multiple GPT-5.1 variants appear to be tested simultaneously, presumably to tailor performance and costs across use cases.
- Tests reportedly use different “thinking budgets”, likely indicating variations in context window size, compute allocation, or depth of reasoning.
- Early signals mention a bigger context window for some GPT-5.1 snapshots and rumored reduced API pricing, which would affect developer and enterprise adoption dynamics.
One leak also suggested two low-latency GPT-5.1 snapshots arriving within a matter of weeks, and a model trained specifically for data analysis slated for early next year. These items remain unconfirmed and seem to reflect internal experimentation rather than finalized product plans.
Timing and competitive context
The timing of these discoveries aligns with competitive pressure from Google, as OpenAI appears to position its next update ahead of Google’s planned Gemini 3 Pro preview. Both companies have been focusing on expanding context windows and improving nuanced problem-solving, and the GPT-5.1 traces may represent OpenAI’s effort to keep pace.
Availability and unknowns
Details about a public rollout, tiered availability, pricing changes, or performance benchmarks are not confirmed. The models have reportedly surfaced in internal testing environments and sometimes under obfuscated names, suggesting staged experiments before any broader release. It is currently unclear whether all rumored variants will be launched simultaneously or whether some will be limited to specific tiers or API access initially.
TestingCatalog continues to monitor for official clarification, benchmarks, and release timelines as competition intensifies in the lead-up to Gemini 3 Pro’s debut.
Original source: https://www.testingcatalog.com/openai-readies-gpt-5-1-thinking-model-ahead-of-gemini-3-pro/?
