OpenAI Adds Transparent Backgrounds to GPT-Image-2 in API Preview
OpenAI added transparent-background output in preview for gpt-image-2 and gpt-image-2-2026-04-21 across the Images API and Responses API image-generation tool, with PNG or WebP output required.
OpenAI added transparent-background output in preview for gpt-image-2 and gpt-image-2-2026-04-21 on August 20. The change applies to the Images API and the Responses API image-generation tool, giving developers a way to request reusable image assets without an opaque background. (OpenAI Developers on X; OpenAI API changelog)
The update is aimed at assets that need to move between contexts: product imagery, graphic design, website mockups, and marketing campaigns. It is an API capability, not a claim that every image will automatically have a clean cutout for every prompt. (OpenAI Developers on X)
Request transparency with the background parameter
OpenAI's image-generation guide supports transparent, opaque, and auto as background values. To request transparency for GPT-Image-2, set background: "transparent". (OpenAI image-generation guide)
The output format matters: OpenAI says transparent backgrounds require PNG or WebP output. JPEG does not support transparent backgrounds, so a workflow that needs an alpha channel should keep the result in one of the supported formats. (OpenAI API changelog; OpenAI image-generation guide)
Where the preview fits
The transparent-background option is available in preview for both gpt-image-2 and the dated gpt-image-2-2026-04-21 model identifier. The changelog lists the Images API endpoints and the Responses API image-generation tool as supported surfaces. (OpenAI API changelog)
That makes the feature useful for applications that generate or edit assets as part of a larger workflow. A product catalog could place a generated object on different layouts; a design tool could keep an icon or illustration separate from the page background; and a campaign pipeline could reuse one asset across multiple compositions. These are direct applications of the transparent output described by OpenAI, not guarantees about a particular prompt or composition quality.
A small implementation checklist
- Set
backgroundtotransparent. - Request PNG or WebP output.
- Preserve the alpha channel when saving or transforming the returned bytes.
- Treat the feature as preview functionality and test the prompts and downstream image handling used by your application.
OpenAI's official guide also notes that background can be auto or opaque when a transparent result is not required. The important boundary for this release is that transparent output is preview-only for the listed GPT-Image-2 model identifiers, and JPEG is not a supported transparent format. (OpenAI image-generation guide)
Sources
- OpenAI Developers on X, "Transparent backgrounds are now available in preview for GPT-Image-2 in the API": https://x.com/OpenAIDevs/status/2090536933571330440
- OpenAI API Changelog, "Transparent backgrounds for GPT-Image-2": https://developers.openai.com/api/docs/changelog
- OpenAI Developers, "Image generation": https://developers.openai.com/api/docs/guides/image-generation
Read next
Keep building the workspace playbookOpenAI: Responses API web search can now return image results
OpenAI added image results to the Responses API web_search tool, letting apps retrieve web-grounded visuals (with source links) alongside regular text results.
OpenAI Cuts GPT-5.6 Luna and Terra Prices, Renames Priority Processing to Fast Mode
OpenAI reduced GPT-5.6 Luna pricing by 80% and Terra by 20%, and on July 30 renamed Priority processing to Fast mode. OpenAI's docs publish Fast mode pricing for Sol, Terra, Luna, and gpt-5.3-codex at 2x the Standard rate; the speed increase to up to 2.5x was specific to Sol.
OpenAI's Secure MCP Tunnel: Connect Private MCP Servers Over Outbound-Only HTTPS
OpenAI's Secure MCP Tunnel connects private and on-prem MCP servers to ChatGPT, Codex, and the Responses API without opening inbound firewall ports. You need a tunnel_id, an API key with Tunnels Read plus Use, and -- separately -- ChatGPT developer-mode access. That permission split is the most common setup blocker.
Frequently Asked Questions
What changed for GPT-Image-2?
OpenAI says transparent backgrounds are available in preview for gpt-image-2 and gpt-image-2-2026-04-21 in the Images API and the Responses API image-generation tool.
How do you request a transparent background?
Set the background parameter to transparent. OpenAI's guide says the output format must be PNG or WebP; JPEG does not support transparent backgrounds.
What can transparent GPT-Image-2 assets be used for?
OpenAI's announcement points to reusable assets for product imagery, graphic design, website mockups, and marketing campaigns. The feature is still in preview, so applications should handle preview behavior as it changes.