AI Token Counter & API Cost Calculator
Estimate token count and API costs across OpenAI, Anthropic, Google, and DeepSeek language models.
Paste any prompt or document to estimate token counts and API costs across Anthropic, OpenAI, and Google Gemini models. Note: character/word heuristics have a ±10–20% margin compared to each provider's official tokenizer endpoint.
Token Count (±10–20%)
Context Window
1,000,000 tokens max0.00% of Claude Sonnet 5.5 context used
Estimated API Cost
Prices checked on 2026-10-16 from Anthropic official pricing.
Current AI API Pricing Table (Checked 2026-10-16)
All rates shown in USD per 1M tokens. Sources: Anthropic Pricing, OpenAI Pricing, Google Gemini Pricing.
| Provider | Model | Input /1M | Output /1M | Cached Input /1M | Notes & Tiers | Source |
|---|---|---|---|---|---|---|
| Anthropic | Claude Opus 5.5 | $4.00 | $20.00 | $0.20 | Cache hit $0.20/1M; batch API 50% off; 1M context window | Official (2026-10-16) |
| Anthropic | Claude Sonnet 5.5 | $2.00 | $10.00 | $0.10 | Cache hit $0.10/1M; batch API 50% off; 1M context window | Official (2026-10-16) |
| Anthropic | Claude Haiku 5.5 | $0.10 | $0.50 | — | Prompts ≤100K tokens; $0.50 / $2.50 above 100K | Official (2026-10-16) |
| Anthropic | Claude Fable 5.1 | $10.00 | $50.00 | $0.25 | Cache hit $0.25/1M; 1M context window | Official (2026-10-16) |
| OpenAI | gpt-6-astra | $10.00 | $50.00 | $1.00 | Cached input $1.00/1M; batch API 50% off | Official (2026-10-16) |
| OpenAI | gpt-6.1-sol | $2.00 | $10.00 | $0.10 | Cached input $0.10/1M; batch API 50% off | Official (2026-10-16) |
| OpenAI | gpt-6-luna | $0.10 | $0.50 | $0.01 | Cached input $0.01/1M; batch API 50% off | Official (2026-10-16) |
| gemini-4-argon | $2.00 | $10.00 | — | Rises to $4 / $20 on 1 Dec 2026; 2M context window | Official (2026-10-16) | |
| gemini-3.8-flash | $0.75 | $3.75 | — | Rises to $1.50 / $7.50 on 1 Jan 2027; 1M context window | Official (2026-10-16) | |
| gemini-3.1-pro-preview | $2.00 | $12.00 | — | Prompts ≤200K; $4 / $18 above 200K; 2M context window | Official (2026-10-16) | |
| gemini-3.1-flash-lite | $0.25 | $1.50 | — | Text/image/video input; 1M context window | Official (2026-10-16) |
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What is the AI Token Counter & API Cost Calculator?
The AI Token Counter estimates token usage and calculates projected API costs across current OpenAI, Anthropic, Google, and DeepSeek language models. It supports cached-input rates, 50% batch API discounts, character-to-token approximations, and daily volume projections directly 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-5, Claude Opus 4.1, Claude Sonnet 4, Gemini 2.5 Pro, etc.).
- Toggle cached-input pricing or 50% batch mode, and adjust expected output token ratio and daily 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 (~4 characters per token / ~1.3 tokens per word) that closely approximates Byte-Pair Encoding (BPE) tokenizers used by modern OpenAI, Anthropic, and Google models.
Are my prompts or API keys transmitted anywhere?
No. Files and text you enter are processed in your browser using JavaScript. No prompts or documents are sent to Heptiq servers.
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.
How does this token counter work?
It uses an industry-standard heuristic algorithm averaging character-based (~4 chars/token) and word-based (~1.3 tokens/word) token estimates for fast, 100% client-side calculation.
Are my prompts sent to any AI servers?
No! All token estimation and cost calculation happens entirely in your web browser. Zero text or API keys are ever transmitted.
Are the pricing rates accurate?
Pricing rates are reference estimates per 1M tokens based on standard developer pricing checked on October 16, 2026. Always verify current list prices on official provider documentation.
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