Short answer: for a real-time, user-facing image generation API in a customer-support application, choose Flux schnell or SDXL Turbo for the first visible result. Flux schnell is the stronger lowest-latency choice at roughly 300–800 ms per image. SDXL Turbo and related Lightning variants sit around 500 ms–1.5 seconds and can be a sensible quality trade. DALL-E 3, at roughly 2–5 seconds, belongs in a slower refinement path rather than a live preview.

The important constraint is per-tenant cost visibility. A fast image is useful only if the support team can tell which tenant requested it, what stage produced it, and what the call cost. I would put model discovery and request accounting in the backend, then let the browser see a thumbnail quickly and request a larger asset only after the user accepts the result.

Which image generation API gives the lowest latency for real-time previews?

In a support console, real time does not mean that every image must be perfect before the agent can continue.…