OpenAI Fine-tuning Pricing 2026
Complete pricing guide with plans, and cost analysis
OpenAI Fine-tuning pricing ranges from $3 to $25/per 1M tokens.
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OpenAI Fine-tuning costs $3 to $25 per per 1M tokens as of May 2026, with 4 plans available. Pricing depends on your chosen tier, contract length, and negotiated discounts.
Use the interactive pricing calculator to estimate your exact cost based on team size and requirements.
- Free tier: No free tier available
OpenAI Fine-tuning offers 4 pricing tiers: GPT-4o mini Fine-tuning, GPT-4o Fine-tuning, GPT-4.1-mini Fine-tuning, Reinforcement Fine-tuning (o4-mini).
Compared to other fine-tuning apis software, OpenAI Fine-tuning is positioned at the budget-friendly price point.
How much does OpenAI Fine-tuning cost?
OpenAI Fine-tuning Pricing Overview
OpenAI Fine-tuning has 4 pricing plans ranging from $3 to $25/per 1M tokens. The GPT-4o mini Fine-tuning plan requires contacting sales for a custom quote. The GPT-4o Fine-tuning plan requires contacting sales for a custom quote. The GPT-4.1-mini Fine-tuning plan requires contacting sales for a custom quote. The Reinforcement Fine-tuning (o4-mini) plan requires contacting sales for a custom quote.
This pricing was last verified in May 30, 2026.
Wind-down notice: OpenAI began winding down self-serve fine-tuning on 2026-05-07. New organizations cannot create training jobs, and all customers will lose access to creating new jobs by 2027-01-06. If you are evaluating this service, plan for migration before that deadline.
OpenAI Fine-tuning lets developers train custom versions of OpenAI's GPT models — including GPT-4o, GPT-4o mini, and GPT-4.1-mini — on proprietary datasets via the API. Pricing is pay-as-you-go, charged per million training tokens with no seat fees or subscriptions. GPT-4.1-mini training is approximately $0.80/1M tokens; GPT-4o training is approximately $25.00/1M tokens. A Reinforcement Fine-tuning option is available for o4-mini at $100/hour of training compute. Fine-tuned model inference is billed at a premium above base model rates.
How OpenAI Fine-tuning Pricing Compares
Compare OpenAI Fine-tuning pricing against top alternatives in Fine-tuning APIs.
All OpenAI Fine-tuning Plans & Pricing
| Plan | Monthly | Annual | Best For |
|---|---|---|---|
| GPT-4o mini Fine-tuning | Custom | Custom | — |
| What's included at GPT-4o mini Fine-tuning
| |||
| GPT-4o Fine-tuning | Custom | Custom | — |
| What's included at GPT-4o Fine-tuning
| |||
| GPT-4.1-mini Fine-tuning | Custom | Custom | — |
| What's included at GPT-4.1-mini Fine-tuning
| |||
| Reinforcement Fine-tuning (o4-mini) | Custom | Custom | — |
| What's included at Reinforcement Fine-tuning (o4-mini)
| |||
View all features by plan (compare side-by-side)
GPT-4o mini Fine-tuning
- Fine-tune GPT-4o mini on custom datasets
- ~$3.00 per 1M training tokens (historical rate; service winding down)
- Inference at a premium over base model rates
- Pay-as-you-go, no seat fees
GPT-4o Fine-tuning
- Fine-tune GPT-4o on custom datasets
- ~$25.00 per 1M training tokens
- ~$3.75 per 1M input tokens (inference)
- ~$15.00 per 1M output tokens (inference)
GPT-4.1-mini Fine-tuning
- Fine-tune GPT-4.1-mini on custom datasets
- ~$0.80 per 1M training tokens (approximate)
- Pay-as-you-go billing
- Inference billed at premium over base rates
Reinforcement Fine-tuning (o4-mini)
- Reinforcement Fine-tuning on o4-mini
- $100 per hour of wall-clock training time (prorated to the second)
- Suitable for reasoning and agentic tasks
- Separate billing from supervised fine-tuning
Compare OpenAI Fine-tuning vs Alternatives
Before committing to OpenAI Fine-tuning, compare pricing with these 3 alternatives in the same category.
How OpenAI Fine-tuning Pricing Compares
| Software | Starting Price | Top Price |
|---|---|---|
| OpenAI Fine-tuning | $3/per 1M tokens | $25/per 1M tokens |
| Predibase | $0.5/per million tokens | $8/per million tokens |
| Together AI Fine-tuning | $0.48/per 1M tokens | $8/per 1M tokens |
| Lamini | Custom | Custom |
OpenAI Fine-tuning Pricing FAQ
01 How is OpenAI Fine-tuning billed?
OpenAI Fine-tuning is billed per million training tokens consumed during the training job. The cost varies by model — for example, GPT-4.1-mini training is approximately $0.80/1M tokens while GPT-4o training is approximately $25.00/1M tokens. Inference on fine-tuned models is billed separately and typically carries a premium over the base model's inference rates.
02 Does OpenAI offer free fine-tuning?
OpenAI does not offer a free tier for fine-tuning. All training jobs are billed on a pay-as-you-go basis per token. You only pay for what you use with no minimum commitment, but there is no free quota for fine-tuning compute.
03 What is Reinforcement Fine-tuning and how does it differ in cost?
Reinforcement Fine-tuning (RFT) is an alternative to supervised fine-tuning that trains reasoning models like o4-mini using reward signals rather than labeled examples. Unlike supervised fine-tuning which is priced per training token, RFT is priced at $100 per hour of wall-clock time in the core training loop, prorated to the second.
04 Is OpenAI Fine-tuning being discontinued?
Yes. OpenAI began winding down self-serve fine-tuning on 2026-05-07. New organizations can no longer create training jobs. All customers will lose access to creating new fine-tuning jobs by 2027-01-06. Existing fine-tuned models and inference may continue under separate terms — check OpenAI's official announcements for the latest details.
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