GPT-5.1 Instant
GPT-5.1 Instant is an API-only (closed weights) language model from OpenAI, released November 13, 2025.
"Today we’re upgrading the GPT‑5 series with the release of: GPT‑5.1 Instant: our most-used model, now warmer, more intelligent, and better at following your instructions. GPT‑5.1 Thinking: our advanced reasoning model, now easier to understand and faster on simple tasks, more persistent on complex ones.
Check it against your own PC →
Lab
OpenAI
Released
November 13, 2025
Weights
API-only (closed weights)
Parameters
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Context
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Price / M tokens
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Epoch ECI
not yet rated
Benchmark results
Epoch AI has not published results for GPT-5.1 Instant yet. New models are usually evaluated within days to weeks.
Links
More from OpenAI
GPT-6.1 Terra · GPT-6.1 Sol · GPT-6 Sol · GPT-6 Luna · GPT-6 Astra · GPT-5.6 Cyber · Daybreak Red · Daybreak Blue