Quick Answer
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OpenAI API costs $0.02 to $270 per per million tokens as of April 2026, with 3 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 API offers 3 pricing tiers: GPT-5.4 mini / nano (Economy), GPT-5.4 / GPT-5.4 Pro (Flagship), Enterprise. The GPT-5.4 / GPT-5.4 Pro (Flagship) plan is high-capability tasks requiring best performance.

Compared to other llm api providers software, OpenAI API is positioned at the mid-market price point.

  • 3 documented hidden costs beyond list price

How much does OpenAI API cost?

OpenAI API pricing starts at $0.02/per million tokens across 3 plans, with enterprise pricing available on request. Plans include GPT-5.4 mini / nano (Economy) (custom pricing), GPT-5.4 / GPT-5.4 Pro (Flagship) (custom pricing), Enterprise (custom pricing).

OpenAI API Pricing Overview

OpenAI API has 3 pricing plans ranging from $0.02 to $270/per million tokens. The GPT-5.4 mini / nano (Economy) plan requires contacting sales for a custom quote and is designed for high-volume, cost-sensitive api workloads. The GPT-5.4 / GPT-5.4 Pro (Flagship) plan requires contacting sales for a custom quote and is designed for high-capability tasks requiring best performance. The Enterprise plan requires contacting sales for a custom quote and is designed for large-scale enterprise api deployments.

There are at least 3 documented hidden costs beyond OpenAI API's list price, including implementation, training, and add-on fees.

This pricing was last verified in April 15, 2026 from 2 independent sources.

OpenAI API pricing starts at $0.10 per million input tokens (GPT-4.1 nano) up to $60 per million output tokens (o1) as of April 2026. All pricing is usage-based with no monthly subscription. GPT-4.1 (flagship) is $2.00/$8.00 per million tokens; o3 (reasoning) is $10.00/$40.00 per million tokens. Prompt caching automatically reduces cached input costs by 50%, and the Batch API cuts all rates in half for async workloads.

All OpenAI API Plans & Pricing

Plan Monthly Annual Best For
GPT-5.4 mini / nano (Economy) Contact Sales Contact Sales High-volume, cost-sensitive API workloads
GPT-5.4 / GPT-5.4 Pro (Flagship) Contact Sales Contact Sales High-capability tasks requiring best performance
Enterprise Contact Sales Contact Sales Large-scale enterprise API deployments
View all features by plan

GPT-5.4 mini / nano (Economy)

  • GPT-5.4 nano: $0.20 input / $1.25 output per M tokens
  • GPT-5.4 mini: $0.75 input / $4.50 output per M tokens
  • Prompt caching: 90% discount on cached input tokens
  • Great for high-volume, cost-sensitive workloads
  • Batch API available at reduced rates

GPT-5.4 / GPT-5.4 Pro (Flagship)

  • GPT-5.4: $2.50 input / $15.00 output per M tokens
  • GPT-5.4 Pro: $30.00 input / $180.00 output per M tokens
  • Long context pricing: GPT-5.4 $5.00/$22.50, Pro $60.00/$270.00
  • Cached input tokens at 90% discount (GPT-5.4 only)
  • Latest flagship models with best performance

Enterprise

  • Volume discounts on API usage
  • Dedicated support and SLAs
  • Custom rate limits and higher concurrency
  • Data processing agreements (DPA)

Usage-Based Rates

Per-unit pricing for OpenAI API API usage.

GPT-5.4 mini / nano (Economy)

Model Unit Rate
GPT-5.4 nano 1M input tokens $0.2
GPT-5.4 nano 1M output tokens $1.25
GPT-5.4 mini 1M input tokens $0.75
GPT-5.4 mini 1M output tokens $4.5
GPT-5.4 nano (cached) 1M cached input tokens $0.02
GPT-5.4 mini (cached) 1M cached input tokens $0.075
  • Prompt caching: 90% discount on cached input tokens
  • Batch API available at reduced rates

GPT-5.4 / GPT-5.4 Pro (Flagship)

Model Unit Rate
GPT-5.4 1M input tokens $2.5
GPT-5.4 1M output tokens $15
GPT-5.4 (cached) 1M cached input tokens $0.25
GPT-5.4 (long context) 1M input tokens $5
GPT-5.4 (long context) 1M output tokens $22.5
GPT-5.4 (long context cached) 1M cached input tokens $0.5
GPT-5.4 Pro 1M input tokens $30
GPT-5.4 Pro 1M output tokens $180
GPT-5.4 Pro (long context) 1M input tokens $60
GPT-5.4 Pro (long context) 1M output tokens $270
  • Prompt caching: 90% discount on cached input (GPT-5.4 only, not available on Pro)
  • Long context pricing applies to extended context windows
  • Batch API available at reduced rates
  • 10% regional processing uplift for data residency endpoints

OpenAI API Year 1 Total Cost by Company Size

Real deployment costs including licenses, implementation, training, and admin — not just the sticker price.

High-Volume Chatbot (nano) $9 Year 1 total

50M input + 10M output tokens/month using GPT-4.1 nano

Production App (GPT-4.1) $26 Year 1 total

5M input + 2M output tokens/month using GPT-4.1

Reasoning Tasks (o3) $13 Year 1 total

500K input + 200K output tokens/month using o3

How OpenAI API Pricing Compares

Software Starting Price Top Price
OpenAI API $0.02/per million tokens $270/per million tokens
Groq Free $3/per million tokens
Together AI $0.03/per million tokens / hour $9.95/per million tokens / hour
Fireworks AI Free $9/per million tokens / hour
Google Gemini API Free $18/per million tokens
Mistral AI API $0.1/per million tokens $6/per million tokens

3 OpenAI API Hidden Costs Beyond the List Price

Beyond the listed price, OpenAI API has at least 3 documented hidden costs that can significantly increase total cost of ownership.

Watch for 3 hidden costs
  • Fine-tuning training costs are additional: $25/M training tokens for GPT-4o mini
  • Image inputs (Vision) cost significantly more — a 1024x1024 image can use 765+ tokens
  • Embeddings are a separate endpoint with separate pricing ($0.02/M tokens for text-embedding-3-small)
Tip

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

Full hidden costs breakdown →

OpenAI API Pricing FAQ

01 How much does the OpenAI API cost?

OpenAI API pricing varies by model. GPT-4.1 nano is $0.10/$0.40 per million tokens (input/output). GPT-4.1 is $2.00/$8.00 per million tokens. The reasoning model o3 is $10.00/$40.00 per million tokens.

02 What is the cheapest OpenAI API model?

GPT-4.1 nano is the most affordable at $0.10 per million input tokens and $0.40 per million output tokens. With prompt caching, cached input drops to $0.025/M tokens.

03 How does OpenAI Batch API work?

The Batch API processes requests asynchronously (within 24 hours) and offers 50% off all model rates. For high-volume workloads without real-time requirements, this halves your API costs.

04 What is prompt caching on OpenAI API?

OpenAI automatically caches repeated input prefixes and charges 50% of the standard input rate for cache hits (vs Anthropic's 10%). Caching is applied automatically for long, repeated contexts.

05 How much does 1 million GPT-4.1 tokens cost?

1M input tokens: $2.00. 1M output tokens: $8.00. With prompt caching on repeated inputs: $1.00/M for cached tokens. Batch API halves all rates: $1.00 input / $4.00 output.

Is this pricing incorrect? — we'll verify and update it.