What is GPT-5.5?
GPT-5.5 is a reasoning model from OpenAI, released on 2026-04-23. It accepts text and image input and returns text output. The recorded context window is 1000K, and the recorded maximum output is 128K. Cataloged capabilities include Reasoning model and Multilingual. The model weights are proprietary and are not published for download. Use the linked references to confirm current access, licensing, and provider-specific limits.
