Price checkPer per 1M tokens
GPT-4o mini Fine-tuningCustomGPT-4o Fine-tuningCustomGPT-4.1-mini Fine-tuningCustom
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All OpenAI Fine-tuning Plans & Pricing

Plan Monthly Annual Best For
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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
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Quick Answer
Last verified:
Estimate

OpenAI Fine-tuning costs $3 to $25 per per 1M tokens as of July 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.

  • 10 documented hidden costs beyond list price
  • Contracts auto-renew — at least thirty days before the start of the next Renewal Term
Last verified:

How much does OpenAI Fine-tuning cost?

OpenAI Fine-tuning pricing ranges from $3 to $25/per 1M tokens across 4 plans. Plans include GPT-4o mini Fine-tuning (custom pricing), GPT-4o Fine-tuning (custom pricing), GPT-4.1-mini Fine-tuning (custom pricing), Reinforcement Fine-tuning (o4-mini) (custom pricing).

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.

OpenAI Fine-tuning contracts auto-renew.

There are at least 10 documented hidden costs beyond OpenAI Fine-tuning's list price, including implementation, training, and add-on fees.

This pricing was last verified in May 30, 2026.

See OpenAI Fine-tuning Plans

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.

Predibase $0.5-$8/per million tokens Compare → Together AI Fine-tuning $0.48-$8.0/per 1M tokens Compare → Lamini Custom pricing Compare →

Compare OpenAI Fine-tuning vs Alternatives

Before committing to OpenAI Fine-tuning, compare pricing with these 3 alternatives in the same category.

VSPredibase
From $0.5/per million tokens

Developers fine-tuning open models without dedicated infra

Full comparison
VSTogether AI Fine-tuning
From $0.48/per 1M tokens

General use

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VSLamini
Custom

General use

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All OpenAI Fine-tuning alternatives & migration guides

What Companies Actually Pay for OpenAI Fine-tuning

Review scores
Third-party review aggregates, as of Jul 2026
Top pricing complaints
Negative experiences due to inefficient software.Deep dissatisfaction and frustration with subscriptions.Bugs, duplicated issues, and generally unreliable service.Repetitive bugs and issues with product functionality.

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
Hugging Face AutoTrain $0.03/month $20/month
Weights & Biases Fine-tuning Free $25/user/month

Detailed pricing comparisons:

Browse all Fine-tuning APIs pricing →

10 OpenAI Fine-tuning Hidden Costs Beyond the List Price

Beyond the listed price, OpenAI Fine-tuning has at least 10 documented hidden costs that can significantly increase total cost of ownership.

Watch for 10 hidden costs
  • Data Preparation $2,000
    high 1 source
    industry "One buyer reported spending approximately $2,000 in support team hours to create 2,400 "high quality" training pairs from 15,000 customer support conversations over three weeks."
  • Training Token Costs $25.00 per 1 million tokens
    medium 1 source
    industry "For instance: * GPT-4o training is priced at $25.00 per 1 million tokens."
  • Inference Token Premium 50%
    medium 1 source
    industry "Fine-tuned model usage carries a 50% premium over base model pricing for both input and output tokens."
  • File Storage $3,650
    low 1 source
    industry "For GPT-3.5, fine-tuning costs $0.008 per 1,000 training tokens."
  • Embeddings Model Selection
    medium 1 source
    industry "For example, text-embedding-3-large costs $0.13 per 1M tokens, while text-embedding-3-small costs $0.02 per 1M tokens."
  • Infrastructure Investment
    medium 1 source
    industry "Infrastructure Investment: Handling rate limits, implementing retry logic, and setting up monitoring for API access require substantial infrastructure investment, even though OpenAI itself does not impose overage fees for rate limiting."
  • Unpredictable Scaling and Inefficient Architectures
    high 1 source
    industry "Over-reliance on large language models (LLMs) for simpler tasks, such as using GPT-4o for sentiment analysis at approximately $0.03 per query instead of a more cost-effective fine-tuned open-source model at around $0."
  • API Call Multiplier
    high 1 source
    industry "API Call Multiplier: Some reports indicate that API calls can cost up to 10 times more than regular tokens."
  • Model Grader Usage
    low 1 source
    industry "Model Grader Usage: If an OpenAI model is used to "grade" outputs during Reinforcement Fine-Tuning, the tokens consumed by these grading calls are billed separately at standard API rates after training."
  • Regional Processing Uplift 10%
    low 1 source
    industry "Regional Processing Uplift: For models released on or after March 5, 2026, that are eligible for data residency, regional processing (data residency) endpoints are charged a 10% uplift."
Tip

Ask your OpenAI Fine-tuning sales rep about these costs upfront. Getting them in writing before signing can save you from surprise charges later.

Full hidden costs breakdown →

Intelligence sourced from 1 independent sources
industry
Key claims include inline source attribution. Data verified against multiple independent sources. 12 source citations total.

OpenAI Fine-tuning Contract Terms

OpenAI Fine-tuning contracts auto-renew. Changes require at least thirty days before the start of the next Renewal Term. These terms are sourced from verified buyer experiences.

Contract Terms
Auto-Renewal Yes
Cancellation Notice at least thirty days before the start of the next Renewal Term
Minimum Commitment non-cancellable if included in an Order Form, unless legally required or specifically permitted
Price Escalation OpenAI may change prices periodically; for subscription price increases, customers are given at least 30 days' notice, with the increase taking effect on the next renewal.
Based on 1 verified source

How to Negotiate OpenAI Fine-tuning Pricing

OpenAI Fine-tuning contracts are negotiable. These 1 tactics are sourced from real buyer experiences and procurement specialists.

Negotiation Playbook 1 tactics
Run a Pilot medium success

industry analysis
High success Medium Low / difficult

Full negotiation guide →

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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