Google Gemini API
Google's Gemini API provides access to Gemini Pro, Flash, and Ultra — Google's state-of-the-art multimodal models with native image, audio, and video understanding. With a 1M+ token context window and competitive pricing, it's a strong alternative to GPT-4 for production workloads.
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.