OpenAI's GPT-5.5 roughly doubles its reasoning over very long documents and writes shorter answers than GPT-5.4 — but it costs twice as much to run.
Compared with GPT-5.4 · the model it replaces
Roughly doubles its reasoning over book-length documents
1M-token input — handling very long documents in one go
74.0%
▲ up from 36.6% · roughly doubled
Writes shorter answers to long prompts
Output length — how much text the model produces
19-34% shorter
▲ vs GPT-5.4 · same prompts
Costs developers twice as much to run
Price per 1M tokens — what developers pay, input / output
$5 / $30
price doubled — was $2.50 / $15
GPT-6 Astra 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.
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