About the Token Price Index
What it is, why it exists, and who built it
What is the TPI?
The Token Price Index (TPI) is a free, public, independent index tracking the cost of AI inference over time. It publishes a single, methodologically transparent number — the geometric mean blended cost across leading AI models from the world's major providers — updated weekly.
Why does this need to exist?
There has never been a published reference index for AI inference pricing. No single number. No transparent methodology.
Token costs are now a utility cost for thousands of organisations — variable, consumption-driven, and increasingly material on the P&L. But unlike electricity, fuel, or labour, there has never been a published reference index for AI inference pricing. No single number. No transparent methodology. No way to say: is the cost of frontier AI moving up or down this quarter, and by how much?
Who built this?
The TPI was built by Harsha Maddipatla, based in Melbourne, Australia.
I built it because I couldn't find it. Token prices are everywhere. Comparison tables, provider pricing pages, the occasional benchmark post. But there's no single published number tracking the cost of frontier AI the way CPI tracks the cost of living. The TPI is my attempt to build that infrastructure — starting with a transparent, equal-weighted geometric mean across active frontier models, with the methodology evolving as the market matures.
The site is completely free. There are no ads, no paywalls, no vendor relationships that influence the data. Pricing is sourced directly from official provider documentation and verified weekly. TPI is funded by my own time as a personal hobby. It has no commercial sponsors, no enterprise tier, and no plans to charge.
Researchers and journalists are welcome to cite TPI in their work for non-commercial purposes. Attribution to tokenpriceindex.com is required, and the data is provided as-is, without warranty — verify current provider pricing independently before relying on it.
If you have feedback, spotted a pricing error, or want to discuss the methodology, I'd love to hear from you.
What's on the site?
The index over time
A time series chart from November 2024 showing how the TPI has moved as the market evolved. Tap any point to see which models drove the change.
The model positioning map
All active index members plotted by price against capability tier (Fast, Mid, Frontier). A quick visual way to see where each provider sits and how much you're paying for each step up in capability.
The cost simulator
Enter your token volume, task type, and daily request frequency. Get daily, monthly, and annual cost estimates across all active index members. The spread between the cheapest and most expensive model is orders of magnitude.
The timeline
A chronological record of every pricing event, model launch, and deprecation in the dataset. Filter by provider, event type, or date range.
The compare page
Side-by-side model comparison with bar charts, price history, and provider-level price evolution over time.
Full methodology transparency
Every model, every price, every step of the calculation is published on the Methodology page. The TPI can be independently verified in a spreadsheet in under five minutes.
What's next
The TPI is a v1. It does what it says — provides a transparent, consistent reference point for AI inference costs — but there is more to build.
Usage-weighted TPI
A usage-weighted variant where models are weighted by actual API traffic rather than equal weighting. We began capturing weekly token volume data in May 2026 and will introduce a weighted variant once the methodology is defensible.
Sub-indices by tier
Frontier, Mid, and Fast sub-indices so users can track the price of the specific tier relevant to their workload rather than a composite across all tiers.
Expanded coverage
More providers, better data, more frequent verification as the market evolves.
Stay in the loop
Share tokenpriceindex.com with anyone thinking about AI costs. For significant updates, reach out at hello@tokenpriceindex.com
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Data updated May 22, 2026 · © 2024–2026 Token Price Index