🏷️ Tech Topics:#Tiktoken#GPT4o#ClaudeTokens#GeminiTokens#LLM_Cost#OpenAI_Pricing#Anthropic_API#BPE_Tokenizer#PromptTokens#TokenEstimator#AIAPICost#ZeroDataLeak
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LLM Token Counter and API Cost Calculator Guide

Measure prompt tokens locally and compare estimated API input and output costs for GPT-4o, GPT-4o mini, Claude 3.5 Sonnet, Gemini Flash, and other listed models. Your prompt remains in the browser throughout the calculation.

✨ Key Capabilities

  • •Uses the browser-safe gpt-tokenizer BPE implementation with GPT-4o o200k_base encoding.
  • •Updates token, word, and character counts as you type or paste.
  • •Estimates total cost from a selectable response-length assumption.
  • •Compares OpenAI, Anthropic, and Google model prices in one table.
  • •Visualizes actual GPT token chunks with alternating highlights.

🚀 How to Use

  1. 1Paste or type a prompt into the text area.
  2. 2Read the live token, word, and character totals.
  3. 3Set the anticipated output-to-input ratio to estimate total request cost.
  4. 4Filter providers and enable Token Visualizer to inspect token chunks.
🔒100% Client-Side Privacy Guarantee

GPT counts are calculated synchronously with gpt-tokenizer, a pure JavaScript BPE implementation compatible with modern OpenAI o200k_base tokenization. Other providers use proprietary tokenizers, so their billed count can differ. Price figures are estimates and should be confirmed before production billing decisions.

💡Technical Deep-Dive & Detailed FAQ Guide

3 questions & detailed answers

Q1.Are prompts sent to a server for token counting?

No. The tokenizer and cost calculation execute entirely in the browser, so prompt content is never transmitted by this tool.

Q2.Is the GPT-4o token count exact?

It uses the o200k_base BPE encoding used by GPT-4o-family models. Chat-message framing and request options can add tokens beyond plain prompt text.

Q3.Why can Claude or Gemini totals differ?

Claude and Gemini use their own tokenizers. The displayed count is a planning baseline; their billing token total may vary.