Models & Releases

GPT-5.5 Instant is starting to roll out in ChatGPT.

ChatGPT users get access to a new model that’s twice as fast with 256K context.

Deep Dive

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Key Points
  • GPT-5.5 Instant offers 2x faster inference than GPT-5, with under 300ms time-to-first-token.
  • Maintains 256K context window, allowing processing of large documents or codebases in one go.
  • Achieves 98% performance parity on major benchmarks while using 40% less compute per inference.

Why It Matters

Faster, more efficient GPT-5.5 Instant gives professionals near-instant responses for complex tasks in ChatGPT.