Claude Opus 5 Token Counter
Count tokens, estimate API costs and check the context window for Claude Opus 5 by Anthropic — all computed locally in your browser.
Runs locally — nothing is uploaded
This model has no official JavaScript tokenizer, so the count is an estimate (CJK text ~1.75 tokens per character, English ~3.5 characters per token).
How Claude Opus 5 compares
Open side-by-side comparison| Model | Provider | Input / 1M | Output / 1M | Context | Out/In ratio |
|---|---|---|---|---|---|
| Claude Opus 5 | Anthropic | $5.00 | $25.00 | 1,000,000 | 5.00× |
| Anthropic: Claude Opus 4.5 | Anthropic | $5.00 | $25.00 | 200,000 | 5.00× |
| Anthropic: Claude Opus 4.8 | Anthropic | $5.00 | $25.00 | 1,000,000 | 5.00× |
| OpenAI: GPT-5.5 | OpenAI | $5.00 | $30.00 | 1,050,000 | 6.00× |
Data source: OpenRouter model API (aggregates official prices, may include platform markup). Rates change - always verify on the official provider page. Last updated 2026-08.
How to Use
This free online token counter counts tokens for Claude Opus 5, a large language model by Anthropic. The tokenizer badge in the tool shows whether the count is exact or estimated: OpenAI-family models are counted with the official tokenizer, while other providers have no public JavaScript tokenizer and are marked as estimates.
Claude Opus 5 offers a context window of 1,000,000 tokens. Open the Context tab to see how much of the window your prompt uses and how many copies of your text fit. Pricing for Claude Opus 5 is 5 USD per 1M input tokens and 25 USD per 1M output tokens; open the Cost tab to estimate the cost of your request in USD and CNY.
Prices are sourced from OpenRouter and last updated 2026-08. Always confirm current rates with the provider's official pricing page before making a purchasing decision. All counting and estimation runs locally in your browser — your text is never uploaded.