Comparative Analysis of AI API Pricing in 2025

As of September 2025, several major AI API providers offer a range of models with varying capabilities and pricing structures. Below is a comparison of the costs associated with using APIs from OpenAI, Google Cloud, Anthropic, and aggregator services.

OpenAI API Pricing:

OpenAI provides several models tailored to different use cases:

  • GPT-5: Designed for complex tasks like coding and reasoning.
    • Input: $1.25 per million tokens
    • Output: $10.00 per million tokens
  • GPT-5 Mini: A faster, more cost-effective version for well-defined tasks.
    • Input: $0.25 per million tokens
    • Output: $2.00 per million tokens
  • GPT-5 Nano: Optimized for summarization and classification tasks.
    • Input: $0.05 per million tokens
    • Output: $0.40 per million tokens

For fine-tuning models, OpenAI offers:

  • GPT-4.1 Fine-Tuning:
    • Input: $3.00 per million tokens
    • Output: $12.00 per million tokens
    • Training: $25.00 per million tokens
  • GPT-4.1 Mini Fine-Tuning:
    • Input: $0.80 per million tokens
    • Output: $3.20 per million tokens
    • Training: $5.00 per million tokens
  • GPT-4.1 Nano Fine-Tuning:
    • Input: $0.20 per million tokens
    • Output: $0.80 per million tokens
    • Training: $1.50 per million tokens

These models are accessible via OpenAI’s API platform. (openai.com)

Google Cloud AI API Pricing:

Google Cloud offers the Gemini series of models:

  • Gemini 1.5 Flash-8B:
    • Input: $0.0375 per million tokens (for prompts ≤ 128k tokens)
    • Output: $0.15 per million tokens (for prompts ≤ 128k tokens)
  • Gemini 1.5 Pro:
    • Input: $1.25 per million tokens (for prompts ≤ 128k tokens)
    • Output: $5.00 per million tokens (for prompts ≤ 128k tokens)

These models are available through Google Cloud’s Vertex AI platform. (ai.google.dev)

Anthropic’s Claude Models:

Anthropic provides the Claude series, including:

  • Claude Opus 4.1:
    • Input: $15 per million tokens
    • Output: $75 per million tokens
  • Claude Opus 4:
    • Input: $15 per million tokens
    • Output: $75 per million tokens

These models are accessible via Google Cloud’s Vertex AI platform. (cloud.google.com)

Aggregator Services:

Aggregator services like Reroute provide access to multiple AI models through a unified API. While specific pricing details for Reroute are not provided in the available sources, such platforms typically offer tiered pricing based on usage volume and the models accessed. For precise pricing, it’s recommended to consult Reroute’s official website or contact their sales team directly.

Additional Considerations:

  • Batch Processing: OpenAI offers a Batch API that allows users to run tasks asynchronously over 24 hours, providing a 50% discount on input and output costs. (openai.com)
  • Priority Processing: OpenAI’s Priority Processing service offers reliable, high-speed performance with the flexibility to pay-as-you-go. (openai.com)
  • Fine-Tuning: OpenAI provides fine-tuning services for their models, allowing customization for specific use cases. Pricing varies based on the model and the extent of customization. (openai.com)

When selecting an AI API provider, consider factors such as model capabilities, pricing structures, and additional services like batch processing or fine-tuning to ensure the solution aligns with your project’s requirements and budget.