Fal.ai
Developer API platform for running image, video, and audio generation models (Flux, SDXL, Whisper, and more) at low latency. Popular as a serverless GPU layer for multimodal AI apps, with a clean Python/JS SDK and pay-per-use pricing.
OpenAI API
API access to GPT-5, GPT-5.5, o3/o4 reasoning models, and the Responses API; plus embeddings, image, audio, and Realtime endpoints. The most widely deployed LLM API in production.