How to Compare LLM API Costs Across Models
Compare LLM API costs fairly: measure tokens on the same prompts, apply provider list prices, include retries, and separate platform fees from BYOK provider bills.
Answer in one line: To compare LLM API costs, run the same prompts on each model, record input/output tokens (or units), multiply by each provider’s current list price, add retries/failures, then scale to monthly volume—keeping platform fees separate from provider bills under BYOK.
This guides searches like compare LLM API costs, AI model cost comparison, and AI inference cost optimization.
Cost formula (simple and honest)
cost ≈ (input_tokens × input_price) + (output_tokens × output_price)
monthly ≈ cost_per_run × runs_per_month × (1 + retry_rate)
Always pull prices from official provider docs—they change.
Fair cost comparison checklist
- Same prompt + same system message
- Same approximate context size
- Record tokens from real runs (not guesses only)
- Include tool/JSON verbosity (wordy models cost more)
- Include failed runs you still pay for
- Separate Smart AI Comparison plan fees from OpenAI/Anthropic/Google bills
Platform fee vs provider fee
| Fee type | Who bills you | Notes |
|---|---|---|
| Platform | Smart AI Comparison | Trial / Starter / Pro / Pro Plus — see Pricing |
| Provider API | OpenAI, Anthropic, Google, etc. | Under BYOK you pay them directly |
Pro (or any paid plan) does not include unlimited provider tokens when you use your own keys.
Tools that help
- AI API cost calculator — illustrative estimates
- AI model pricing — how to think about list prices
- AI API pricing explained — deeper primer
- Cost vs quality vs speed — don’t optimize cost alone
Workflow in Smart AI Comparison
Run side-by-side compares, note usage signals where available, then validate on provider dashboards. Start with the free trial, then subscribe if evaluation volume grows.
CTA: Compare models · View pricing
FAQ
Is the cheapest model always best?
No. Cheap wrong answers create human review cost. Set a quality floor first.
Do annual plans change API token prices?
No. Annual/monthly platform plans change Smart AI Comparison billing, not OpenAI/Anthropic/Google token rates.