OpenAI · lightweight line
The newest GPT Instant model is GPT-5.5 Instant Mini, released on July 6, 2026. OpenAI officially discontinued the line on October 7, 2026.
How long it has been since the last release against the line's usual gap and its recent ones — the rhythm, not a date.
Latest: GPT-5.5 Instant Mini · Jul 6, 2026
Every Monday, only when something shipped: the AI models that came out, what each one changed, and which lines are due next.
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Newest first — what each version changed versus the one before, in OpenAI's own numbers.
It replaces GPT-5.3 Instant Mini as the fallback model ChatGPT users get after reaching their GPT-5.5 Instant or Auto limits; it does not appear in the model picker or the API.
Compared with GPT-5.3 Instant Mini · the model it replaces
OpenAI's new lightweight model: far fewer made-up answers and much stronger math than GPT-5.3 Instant Mini — and it's now the default free model in ChatGPT.
Compared with GPT-5.3 Instant Mini · the model it replaces
Makes up about half as many wrong answers on tricky questions
High-stakes prompts — questions where a wrong answer really matters
52% fewer
▲ vs GPT-5.3 Instant Mini · same tests
Solves 8 in 10 competition-level math problems
AIME 2025 — a hard high-school math competition
81.2
▲ up from 65.4 · +16 points
Now the model free ChatGPT users get by default
Availability — which users get this model without paying
default free ChatGPT
✦ new in GPT-5.5 Instant