Released Apr 24, 20261,050,000 context$5/M input tokens$30/M output tokens
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, enabling large-scale reasoning, coding, and multimodal workflows within a single system.
Recent activity on GPT-5.5
Total usage per day on OpenRouter
Prompt
6.12B
Reasoning
59.5M
Completion
42.1M
Prompt tokens measure input size. Reasoning tokens show internal thinking before a response. Completion tokens reflect total output length.