How does NumStack calculate AI token costs?

NumStack uses real published pricing from OpenAI, Anthropic, Google, and other AI providers. Enter your typical usage (input tokens, output tokens, requests per day) to see projected monthly costs across all models.

Why do different AI models have different token prices?

Different models have different computational costs. Smaller models like GPT-4o mini or Haiku are cheaper but less capable. Larger models like GPT-4o or Claude Sonnet are more powerful but cost more per token.

How can I reduce my AI API costs?

Use smaller models for simple tasks, cache repeated prompts, trim output length (output tokens cost 3-5x more than input), and batch requests instead of real-time when latency allows.

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OpenAI vs Anthropic: Complete Cost Breakdown

Published June 2026 • 8 min read

The Great AI Model Showdown

If you are building AI applications, you have probably wondered: should I use OpenAI or Anthropic? Both offer world-class language models, but they are designed differently and cost very differently.

The Models: Head-to-Head

OpenAI Lineup

GPT-4o: $5/$15 per 1M tokens (input/output)
GPT-4 Turbo: $10/$30 per 1M tokens
GPT-4o mini: $0.15/$0.60 per 1M tokens (best value)
GPT-3.5 Turbo: $0.50/$1.50 per 1M tokens

Anthropic Lineup

Claude 3.5 Sonnet: $3/$15 per 1M tokens
Claude 3 Opus: $15/$75 per 1M tokens (most capable)
Claude 3 Haiku: $0.25/$1.25 per 1M tokens (fastest, cheapest)

Cost Comparison: Real Scenarios

Scenario 1: High-Volume Chatbot (10M tokens/month)

Typical split: 70 percent input, 30 percent output

GPT-4o mini: $19/month
Claude 3.5 Haiku: $31.50/month
GPT-4o: $105/month
Claude 3.5 Sonnet: $63/month

Winner: GPT-4o mini (5.5x cheaper than Sonnet)

Scenario 2: Complex Analysis (1M tokens/month)

Longer inputs/outputs, more reasoning needed

Claude 3.5 Sonnet: $6.30/month
GPT-4o: $10.50/month
Claude 3 Opus: $18/month
GPT-4 Turbo: $20/month

Winner: Claude 3.5 Sonnet (best quality for the price)

Which Model Should You Use?

Decision Framework

Budget is primary concern? Use GPT-4o mini or Claude Haiku
Balance of cost and quality? Use Claude 3.5 Sonnet or GPT-4o
Absolute best quality? Use Claude 3 Opus or GPT-4 Turbo
Speed critical? Use Claude Haiku or GPT-4o mini

Key Differences Beyond Price

Context Window

OpenAI: 128K tokens. Anthropic: 200K tokens. Anthropics longer context is better for large documents.

Output Quality

Claude produces more nuanced responses. GPT-4o is faster and more direct.

API Reliability

Both are excellent. Pick based on your use case, not reliability concerns.

Pro Tips: Save 30-50 percent on Costs

Use smaller models for simple tasks (10x lower cost)
Use batch APIs for non-real-time work (50 percent discount)
Use prompt caching for repeated inputs
Cap max_tokens to force concise responses (saves 20-40 percent)
Use RAG instead of passing huge documents every time

The Bottom Line

For most startups: Start with Claude 3.5 Haiku or GPT-4o mini. They are cheap, fast, and handle 90 percent of real-world tasks.

For higher quality: Claude 3.5 Sonnet and GPT-4o are nearly identical. Pick whichever you already use.

Do not use anything more expensive than Sonnet/GPT-4o unless you have a specific reason.