fal.ai is a serverless AI inference platform built for speed, offering sub-second latency for image, video, and audio generation models. It hosts popular open-source models including FLUX, Stable Diffusion, Wan2.1, and dozens more via a simple REST API. Developers can deploy custom models or use pre-built endpoints without managing infrastructure. Features include real-time streaming, a browser-based playground, webhooks, and pay-per-use pricing. Widely used by AI app developers who need fast, scalable image and media generation APIs.