---
id: "openai/gpt-5.5"
also: ["openai/gpt-5.5-20260423", "requesty/openai/gpt-5.5", "vercel/openai/gpt-5.5"]
card_usd_per_m: "5.0 in, 30.0 out, at openai"
cheapest_list_usd_per_m: "2.5 in, 15.0 out, at openai/flex on openrouter"
cheapest_effective_usd_per_m: "0.9646 in, 15.0 out, at openai/flex on openrouter"
context: 1050000
max_output: 128000
input: ["file", "image", "text"]
output: ["text"]
released: "2026-04-24"
reasoning: ["xhigh", "high", "medium", "low", "none"]
api: ["/api/v1/chat/completions", "/api/v1/completions", "/api/v1/messages", "/api/v1/responses"]
params: ["include_reasoning", "max_completion_tokens", "max_tokens", "reasoning", "reasoning_effort", "response_format", "seed", "stop", "structured_outputs", "temperature", "tool_choice", "tools", "verbosity"]
endpoints: 19
gateways: "openrouter (8), requesty (8), vercel (3)"
no_training: 18
trains: 0
retains_prompts: 7
coding: 74.9000
agentic: 36.4000
---
# OpenAI: GPT-5.5

GPT‑5.5 understands what you’re trying to do faster and can carry more of the work itself. It excels at writing and debugging code, researching online, analyzing data, creating documents and spreadsheets, operating software, and moving across tools until a task is finished. Instead of carefully managing every step, you can give GPT‑5.5 a messy, multi-part task and trust it to plan, use tools, check its work, navigate through ambiguity, and keep going.