Together AI

Together AI: Complete Review

Together AI has built a comprehensive cloud platform for open source AI that goes beyond simple inference. While many providers offer API access to models, Together AI adds fine-tuning, GPU clusters for training, and batch processing, creating a full lifecycle platform for organizations working with open source models.

Inference Options

The platform offers two distinct inference modes. Serverless inference charges per token, making it cost-effective for variable workloads. Dedicated endpoints provision single-tenant GPUs for applications that need predictable latency and isolation. This flexibility means organizations can choose the right trade-off between cost and performance for their use case.

Training and Fine-Tuning

Beyond inference, Together AI provides fine-tuning services that let organizations adapt open source models to their specific needs. GPU clusters with H100 and B200 hardware are available for training workloads. This combination means organizations can start with pre-trained models, fine-tune them on proprietary data, and deploy the resulting custom models, all within one platform.

Model Catalog

With over 200 models available, Together AI offers one of the largest selections of open source models accessible via API. The catalog includes DeepSeek V3.1 (671B parameters, 37B activated), Qwen3.5 397B (MoE with 17B activated parameters), MiniMax M2.5 (optimized for agentic coding), and GPT-OSS (OpenAI's open source reasoning models). This range covers chat, audio, image, and vision use cases.

Developer Features

Together AI includes practical features for production deployments. Batch inference queues asynchronous generation jobs for cost-effective processing. Code execution runs Python alongside model calls. Structured outputs ensure reliable JSON responses using defined schemas. AI evaluations automate scoring using LLM judges. The OpenAI-compatible API means existing client code works with minimal changes.

Strengths

Over 200 open source models available via API

Serverless inference with per-token pricing

Dedicated GPU endpoints for predictable latency

Fine-tuning API for custom model adaptation

GPU clusters (H100, B200) available for training

Batch inference for cost-effective async processing

Structured outputs ensure reliable JSON responses

OpenAI-compatible API reduces integration effort

Limitations

Per-token pricing can become expensive at high volumes

No free tier beyond initial credits

Requires cloud dependency with no self-hosted option

Model quality varies across the catalog

Less brand recognition than OpenAI or Anthropic

Verdict

Together AI is the best choice for developers and organizations that want a comprehensive platform for open source AI, covering inference, fine-tuning, and training. Its large model catalog and flexible deployment options make it a strong alternative to proprietary API providers. For organizations committed to open source AI, Together AI offers the most complete ecosystem available.