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AI Fine-Tuning Pricing Comparison

Fine-tuning lets you train a pre-existing AI model on your own data to specialize it for your domain, format, or task -- compare training and inference costs across all major providers.

Models Compared

14

Cheapest Training

$0.48/M tokens

Free Training

2 models

Fine-Tuning Pricing by Model
ProviderModelTraining $/MInference Input $/MInference Output $/MMin ExamplesHosting
GoogleGemini 2.0 FlashFree$0.10$0.40100Managed
GoogleGemini 1.5 FlashFree$0.075$0.30100Managed
Together AILlama 3.1 8B$0.48$0.18$0.181Managed
FireworksLlama 3.1 8B$0.50$0.20$0.201Managed + Self-host
MistralMistral Small$2.00$0.10$0.301Managed
CohereCommand R$2.00$0.15$0.602Managed
OpenAIGPT-4o Mini$3.00$0.30$1.2010Managed
Together AILlama 3.1 70B$3.50$0.88$0.881Managed
FireworksLlama 3.1 70B$4.00$0.90$0.901Managed + Self-host
CohereCommand R+$5.00$2.50$10.002Managed
MistralMistral Medium$6.00$2.50$7.501Managed
OpenAIGPT-3.5 Turbo$8.00$3.00$6.0010Managed
Together AILlama 3.1 405B$8.00$5.00$5.001Managed
OpenAIGPT-4o$25.00$3.75$15.0010Managed
Fine-Tuning vs Prompt Engineering
FactorFine-TuningPrompt Engineering
Setup TimeHours to days (data prep + training)Minutes to hours
Upfront CostTraining tokens cost (see table above)None
Per-Request CostLower (shorter prompts needed)Higher (long system prompts + few-shot examples)
Iteration SpeedSlow (retrain on each change)Fast (edit prompt and test)
Best ForConsistent formatting, domain expertise, production workloadsPrototyping, general tasks, low volume
Data RequirementNeed curated training examplesNo training data needed
When Fine-Tuning Makes Sense

Good Reasons to Fine-Tune

  • +Your prompts are consistently long and repetitive, driving up inference costs
  • +You need a specific output format that the base model struggles to maintain
  • +You have domain-specific terminology or style requirements
  • +High volume production use where per-token savings compound
  • +You want faster response times by eliminating lengthy few-shot examples

When to Avoid Fine-Tuning

  • -You are still experimenting with prompts and do not have a stable use case
  • -Prompt engineering or retrieval-augmented generation (RAG) already works well
  • -You have fewer than 50 quality training examples
  • -Your task changes frequently and you would need to retrain often
  • -Low request volume where training cost will not be recouped
How to Estimate Fine-Tuning ROI

Fine-tuning has an upfront training cost but can reduce ongoing inference costs by shortening your prompts. To estimate whether fine-tuning pays off:

  1. Measure your current prompt length. Count the tokens in your system prompt and few-shot examples. A typical few-shot prompt might use 500-2,000 tokens per request.
  2. Estimate post-fine-tuning prompt length. Fine-tuned models can typically drop few-shot examples entirely, reducing input to just the user query (50-200 tokens).
  3. Calculate token savings per request. Multiply the saved input tokens by the per-token input price.
  4. Compute break-even volume. Divide the total training cost by the per-request savings. For example, if training costs $50 and you save $0.005 per request, you break even after 10,000 requests.

For most production applications with over 10,000 monthly requests, fine-tuning typically pays for itself within the first month.

Frequently Asked Questions

Fine-tuning is the process of training a pre-trained language model on your own dataset to specialize it for a specific task, domain, or output style. Instead of training from scratch, you adapt an existing model using examples of the inputs and outputs you want.

OpenAI charges $25.00 per million training tokens for GPT-4o fine-tuning. After training, inference costs $3.75 per million input tokens and $15.00 per million output tokens. You need a minimum of 10 training examples, though OpenAI recommends 50-100 for best results.

Yes, Google currently offers free training for Gemini 2.0 Flash and Gemini 1.5 Flash fine-tuning. You only pay for inference after training. However, Google requires a minimum of 100 training examples, which is higher than most other providers.

The minimum varies by provider: Together AI and Fireworks require just 1 example, Cohere requires 2, OpenAI requires 10, and Google requires 100. In practice, most fine-tuning jobs benefit from at least 50-100 high-quality examples, with diminishing returns above 1,000.

For zero training cost, Google Gemini models offer free fine-tuning. For open-source models, Together AI offers Llama 3.1 8B training at $0.48 per million tokens, making it the cheapest paid option. Fireworks also offers competitive pricing with the added benefit of self-hosting your fine-tuned model.

Use prompt engineering first -- it requires no upfront cost and is easy to iterate on. Fine-tuning makes sense when you need consistent formatting, domain-specific behavior, lower per-request latency, or when your prompts are getting too long and expensive. Fine-tuning can actually reduce inference costs by removing the need for lengthy system prompts.

Yes, but options vary by provider. Fireworks explicitly supports both managed hosting and self-hosting of fine-tuned models. Open-source models (Llama, Mistral) fine-tuned through Together AI or Fireworks can typically be exported and self-hosted. OpenAI and Google fine-tuned models can only run on their respective platforms.