GPT-5.5 Instant
GPT-5.5 Instant is an API-only (closed weights) language model from OpenAI, released May 5, 2026.
We’re updating ChatGPT’s default model, available to everyone, to be smarter and more accurate, with clearer, more concise answers that feel better tailored to you. Because Instant is the daily driver for hundreds of millions of people, small improvements make a big difference.
Check it against your own PC →
Lab
OpenAI
Released
May 5, 2026
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-5.5 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