What differs
- Models: Vertex AI tunes Gemini models and open models such as Gemma 3, Llama, and Qwen 3; Bedrock fine-tunes Amazon Nova, Meta Llama 3.x, and Claude 3 Haiku, with model-specific regions.
- Methods: Vertex AI lists SFT, preference tuning (Gemini 2.5 Flash and Flash-Lite), and RL fine-tuning (Gemini 3.5 Flash and 3.1 Flash-Lite); Bedrock lists SFT, reinforcement fine-tuning with Lambda reward functions, and distillation.
- Pricing: Vertex AI publishes per-token tuning prices (for example Gemini 2.5 Flash $0.005 per 1,000 training tokens); Bedrock publishes RFT at $80.00 per training hour for gpt-oss-20b and Qwen3 32B plus $1.95 monthly storage.
- Weights: neither profile lists a path to export tuned closed-model weights.
- Published security: Google lists Generative AI on Agent Platform in SOC 2, ISO/IEC 27001, and HIPAA scope; AWS states Bedrock is in scope for ISO and SOC programs, HIPAA eligible, and FedRAMP High in GovCloud (US-West).
Who each tends to fit
The choice usually follows the cloud your data and security reviews already sit in, and which model family you need to tune. Check method support for your exact model first.
Last checked: . No winner declared.