AI Token Counter & API Cost Calculator
Estimate token count and API costs for OpenAI (GPT-4o), Anthropic (Claude 3.5), and Google (Gemini) models.
Paste any text to estimate token count and API cost across OpenAI, Anthropic, and Google AI models. Uses a heuristic approximation (~4 chars/token).
Token Count
Context Window
128,000 tokens max0.00% of GPT-4o context used
Estimated Cost
⚠️ Reference pricing — verify current rates with official provider documentation before budgeting.
AI API Pricing Reference Table
* Reference pricing estimates per 1M tokens. Always verify current rates at platform.openai.com, console.anthropic.com, or aistudio.google.com.
| Model | Provider | Input /1M tokens | Output /1M tokens | Context Window |
|---|---|---|---|---|
| GPT-4o | OpenAI | $2.500 | $10.000 | 128,000 |
| GPT-4o mini | OpenAI | $0.150 | $0.600 | 128,000 |
| GPT-4 Turbo | OpenAI | $10.000 | $30.000 | 128,000 |
| Claude 3.5 Sonnet | Anthropic | $3.000 | $15.000 | 200,000 |
| Claude 3 Haiku | Anthropic | $0.250 | $1.250 | 200,000 |
| Gemini 1.5 Pro | $1.250 | $5.000 | 2,000,000 | |
| Gemini 1.5 Flash | $0.075 | $0.300 | 1,000,000 |
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How to use the AI Token Counter & Cost Calculator
?Frequently Asked Questions
What is the AI Token Counter & API Cost Calculator?
The AI Token Counter estimates token usage and calculates projected API costs across OpenAI, Anthropic, and Google language models. It provides real-time character-to-token ratio approximations, input/output cost modeling, and daily volume projections entirely in your browser.
Who is the AI Token Counter & API Cost Calculator for?
Built for AI developers, prompt engineers, SaaS builders, and product teams building with LLM APIs seeking to estimate, monitor, and optimize API token costs.
How to Use the AI Token Counter & API Cost Calculator
- Paste your prompt, system instructions, or context into the editor.
- Select your target AI model (GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 Pro, etc.).
- Adjust expected output token percentage and daily request volume.
- View estimated token counts, context window utilization, and per-request/monthly cost projections.
Worked Calculation Example
Frequently Asked Questions
How does this token counter estimate token counts?
It uses a hybrid character and word heuristic algorithm (~4 characters per token / ~1.3 tokens per word) that closely approximates Byte-Pair Encoding (BPE) tokenizers used by GPT-4 and Claude.
Are my prompts or API keys transmitted anywhere?
No! All calculations execute 100% locally in your browser using JavaScript. No prompts, documents, or data are ever sent over the network.
Why do AI providers charge different rates for input vs output tokens?
Processing input tokens is parallelized on GPUs during prompt evaluation (prefill phase), whereas generating output tokens requires sequential autoregressive token-by-token generation (decode phase), consuming significantly more compute time and GPU memory bandwidth.
What is the token-to-word ratio for English text?
For typical English prose, 1 token is approximately 0.75 words (or 1,000 tokens ≈ 750 words). Technical documentation, code snippets, and non-English languages typically have higher token-to-word ratios.
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