Claude Sonnet 4.5 token counter
Type or paste a prompt to count Claude Sonnet 4.5 tokens and estimate what it costs to run — free, live, and private.
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Counts include each model's own chat-template overhead.
128 charsClaude Sonnet 4.5
Anthropic · 200k context…tokens
About Claude Sonnet 4.5 tokenization
- Vendor
- Anthropic
- Context window
- 200k tokens
- Pricing (per 1M tokens)
- $3 input · $15 output (as of 2026-07-07)
- How we count
- Anthropic's official count-tokens API, since its tokenizer isn't public
FAQ
How accurate is this Claude Sonnet 4.5 token count?
Exact when a server API key is configured — counts come from Anthropic's own count-tokens endpoint. Otherwise a clearly-labeled local estimate is shown.
Does my prompt leave the browser?
Only to Anthropic's count-tokens API (which doesn't run the model or store your prompt) — nothing is logged by this site.
What does a Claude Sonnet 4.5 request cost?
Input tokens × $3/1M plus output tokens × $15/1M (standard tier, as of 2026-07-07). The calculator above does this for your actual prompt.