GPT Image 2 API Guide
How to call GPT Image 2 via the OpenAI Images API: endpoints, parameters, supported sizes, output formats, and known limitations as of April 2026.
TL;DR
GPT Image 2 is accessible through the OpenAI Images API using the model identifier 'gpt-image-alpha' (subject to change). It supports text-to-image generation, image editing with a mask, and multi-turn image refinement. As of launch documentation, supported sizes are 1024×1024, 1024×1536, and 1536×1024. All information below is sourced from the April 2026 launch docs.
Key facts
- →Endpoint: POST /v1/images/generations (generation) and POST /v1/images/edits (editing)
- →Model parameter: 'gpt-image-alpha' as documented at launch — verify the current identifier in the OpenAI API reference
- →Quality parameter: 'low', 'medium', or 'high' (controls both output quality and cost)
- →Supported sizes at launch: 1024×1024, 1024×1536, 1536×1024
- →Response format: base64-encoded PNG or URL (url response expires after a short window)
- →Editing endpoint accepts an image + optional mask; input image tokens are billed separately
- →Rate limits vary by tier — see the limits guide for details
FAQ
What SDK version supports GPT Image 2?
The official OpenAI Python and Node.js SDKs gained support at or shortly after the April 21, 2026 general release. Update to the latest SDK version and confirm the model identifier in the OpenAI changelog before deploying.
Can I generate images larger than 1536px?
At launch, 1536px was the maximum dimension documented. OpenAI has not announced higher resolutions for GPT Image 2 as of April 2026. Monitor the official changelog for updates.
Is streaming supported for image generation?
The standard Images API returns a completed image, not a streamed token sequence. Partial-image streaming has not been documented for GPT Image 2 at launch.
Can I use GPT Image 2 for commercial projects?
Usage is governed by OpenAI's usage policies and your API agreement. Review the current OpenAI usage policy page for commercial licensing terms, as these can change independently of the technical release.