OpenAI: gpt-5.5
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.
Inputs used for the providers' own purposes
At least one provider of this model uses your inputs for its own purposes, for example to train AI models. Do not enter personal data of third parties or sensitive data. You can object to this use at any time in your account settings or via "Manage consents" in the chat.
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Uptime
Performance
Usage & Ranking
Supported parameters
All providers = every upstream serving this model supports it. Some providers = depends on which upstream handles the request. Default = the value sent when you leave the parameter unset.
| Parameter | Providers | Default |
|---|---|---|
| frequency_penalty | Some providers | Not sent by default |
| include_reasoning | All providers | - |
| max_completion_tokens | Some providers | - |
| max_tokens | All providers | - |
| presence_penalty | Some providers | Not sent by default |
| reasoning | All providers | - |
| reasoning_effort | All providers | - |
| repetition_penalty | Some providers | Not sent by default |
| response_format | All providers | - |
| seed | All providers | - |
| structured_outputs | All providers | - |
| temperature | Some providers | Not sent by default |
| tool_choice | All providers | - |
| tools | All providers | - |
| top_k | Some providers | Not sent by default |
| top_p | Some providers | Not sent by default |
| verbosity | All providers | - |