GPT-5.5 was released by OpenAI on April 23, 2026, as a flagship model in the GPT line.
OpenAI's GPT-5.5 roughly doubles its score on a 1M-token long-document test and solves more command-line coding tasks than GPT-5.4 — but its API price doubles.
Compared with GPT-5.4 · the model it replaces
Roughly doubles its score at finding facts across book-length input
OpenAI MRCR v2 (8-needle, 512K-1M tokens) — finding and linking facts across book-length input
74.0%
▲ up from 36.6% · roughly doubled
Solves more command-line coding tasks
Terminal-Bench 2.0 — complex command-line coding workflows
82.7%
▲ up from 75.1% · +7.6 points
Costs developers twice as much to run
Price per 1M tokens — what developers pay, input / output
$5 / $30
price doubled — was $2.50 / $15
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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GPT-6.1 Sol is the current model in this line. The card shows 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-6.1 Sol · Sep 29, 2026
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