Groq, Together AI, and Fireworks AI are the three most important fast inference platforms for open source LLMs. Groq is the fastest raw inference platform available (700-800 tokens/second on Llama models using custom LPU chips), Together AI has the broadest model selection and good pricing for fine-tuning, and Fireworks specializes in production-ready inference with strong function calling support. All three are significantly cheaper than running GPT-4o or Claude Sonnet, making them worth evaluating for any high-volume workload where an open source model is good enough.
Why These Platforms Exist
Running large language models on GPU clusters is operationally complex and capital-intensive. Groq, Together AI, and Fireworks AI have all built specialized inference infrastructure that lets developers access open source models through a simple API, without managing any infrastructure.
The value proposition is threefold:
- Cost: Open source model inference is 5-50x cheaper than GPT-4o or Claude Sonnet for equivalent output quality on many tasks.
- Speed: Dedicated inference infrastructure often delivers faster responses than OpenAI and Anthropic, especially under load.
- Model flexibility: Access to hundreds of open source models, including domain-specific fine-tunes that outperform general models on specific tasks.
Groq: The Speed Leader
Groq uses custom Language Processing Units (LPUs) designed specifically for transformer inference. The result is inference speeds of 700-900 tokens per second on Llama 3 8B, and 200-400 tokens per second on Llama 3 70B. For comparison, GPT-4o typically delivers 50-100 tokens per second.
This speed advantage is meaningful for latency-sensitive applications: real-time voice interfaces, interactive coding tools, applications where users experience the model typing character by character.
Groq pricing (May 2026):
- Llama 3.1 8B: $0.05/1M input, $0.08/1M output
- Llama 3.1 70B: $0.59/1M input, $0.79/1M output
- Llama 3.1 405B: $2.00/1M input, $2.00/1M output
- Gemma 2 9B: $0.20/1M input, $0.20/1M output
Free tier: Groq offers a free tier with rate limits – useful for prototyping. Check console.groq.com for current limits.
Groq limitations: Model selection is narrower than Together AI or Fireworks. Groq focuses on a curated set of top-performing open source models rather than offering everything available. No fine-tuned model hosting. Context window on some models is more limited than native offerings.
Best for: Any application where low latency matters, voice interfaces, interactive tools, development and prototyping.
