o1 / o3 Token Calculator — Count Tokens & Estimate API Cost
o1 / o3 Token Calculator is a free, browser-based developer tool that counts tokens for o1 / o3 using the official OpenAI o200k_base tokenizer and forecasts API costs in real time. Unlike word-based counters, it returns reliable token counts and live API cost estimates entirely in your browser: no uploads, no API keys, no sign-up. It is one of 90+ models covered by TokenCalc, a free AI token calculator for developers.
→ Open the o1 / o3 token counter — paste any prompt or document, get token counts and cost estimates in seconds.
o1 / o3 pricing (2026)
| Model | Tokenizer | Input / 1M tokens | Output / 1M tokens | Context window |
|---|---|---|---|---|
| o1 | o200k_base | $15.00 | $60.00 | 200K |
| o3 | o200k_base | $2.00 | $8.00 | 200K |
o1 / o3 token counter by the numbers
- 90+ LLM tokenizers supported in one free tool
- 200K token context window on o1 / o3
- 1.3 average tokens per English word
- $2.00 / $8.00 per 1M input / output tokens for o3 (o1 runs $15.00 / $60.00)
- 100% in-browser — your text never leaves the device
- 0 uploads, 0 API keys, 0 cost
How many tokens is a word in o1 / o3?
One English word averages ~1.3 tokens (roughly 4 characters per token). The exact ratio depends on your text:
- Common short words are often a single token.
- Long or technical words split into several tokens.
- Code and special characters tokenize more densely than prose.
- Chinese text runs ~0.6–1.2 tokens per character.
Why count o1 / o3 tokens?
- Budget context — know how many tokens a document takes before it enters your prompt.
- Forecast costs — see the exact $ cost of a request at per-1M-token rates.
- Compare models — the same text tokenizes differently across model families.
o1 / o3 token counter — free and private
Our AI Token Calculator covers o1 / o3, plus exact token counts for GPT-5, GPT-4o, o1, o3 (official tiktoken) and 90+ more models — all in your browser, no upload, no API key.
→ Open the o1 / o3 token counter (free, private)
o1 / o3 token FAQs
How many tokens is a word in o1 / o3?
One English word averages about 1.3 tokens (roughly 4 characters per token). Chinese text runs around 0.6–1.2 tokens per character. Always verify with a real token counter.
How much does o1 / o3 API cost per 1M tokens?
See the pricing table on this page for o1 / o3 input and output rates per 1M tokens.
Is the o1 / o3 token counter private?
Yes. Everything runs locally in your browser — your text never leaves your device, no uploads, no API keys, no sign-up.
What is a token in o1 / o3?
A token is the smallest unit of text a model’s tokenizer processes — roughly one English word equals 1.3 tokens. A model’s context window is measured in tokens, so an accurate count tells you how much text fits in a prompt.
Why should I count tokens for o1/o3 reasoning models?
Reasoning models generate hidden chain-of-thought tokens that you are billed for, so the real cost per request is often higher than the visible output. Counting input tokens precisely with the official tokenizer helps you forecast that spend.