About toksum.dev

What this is

toksum.dev is a free cost calculator for LLM APIs — OpenAI, Anthropic, Google, Mistral, xAI, DeepSeek, Meta (via Groq), Cohere, and more. Side-by-side comparisons, batch discount and prompt-cache modeling, and a token counter that runs entirely in your browser. The goal: help developers and product teams predict their bill before they ship a feature, not after the surprise invoice arrives.

Who runs it

One developer in South Korea, building in public. I started this after spending a weekend hand-comparing Claude Sonnet 4.6, GPT-5.5, and Gemini 2.5 Pro for a side project and realizing the existing comparison sites either skipped batch pricing, ignored prompt caching, or hadn't been updated since the last price drop. So I wrote the calculator I wished existed.

You can follow build progress on Twitter/X or reach me at [email protected].

How pricing data is maintained

All model prices are sourced from each provider's official pricing page and hand-checked. There is no automated scraping — if OpenAI cuts a price or Anthropic adds a new tier, the data is updated manually with a date stamp. This is slower than a scraper but catches edge cases scrapers miss: batch discounts, regional variants, deprecation dates, cached-input pricing, tiered long-context rates.

If you spot a stale or wrong number, please email — it'll be fixed the same day and you'll be credited on the changelog.

How it stays free

The Free tier covers every calculator and guide. Display ads on the free tier offset the hosting bill. A Pro subscription ($7/mo) removes ads and unlocks calculation history, project tagging, CSV export, and custom model pricing for fine-tunes. No data sold, no upsell walls — just a way to keep the lights on.

Contact

Email: [email protected]
Twitter/X: @toksum_dev