TokenCalculator.dev - Privacy-First LLM Token Calculator for Developers and AI Teams
TokenCalculator.dev is a browser-based tool that counts tokens and estimates API costs from text, PDF, DOCX, code, data files, and images—all processed locally without uploading any content. It supports major LLM providers including OpenAI (GPT-5.6 series), Anthropic (Claude 4.8/5 series), Google (Gemini 2.5/3.1), and DeepSeek (V4 series), providing exact BPE tokenization for OpenAI and deterministic provider-calibrated projections for others.
Key Features
- Privacy-first architecture: All text extraction, image dimension reading, and token calculations run entirely in your browser—zero data leaves your device
- Multi-format input support: Paste text directly or attach PDF, DOCX, code files (.js, .ts, .py, .go, .rs, etc.), data files (.json, .csv, .yaml, .sql), and images (PNG, JPEG, WebP, GIF) up to 12 MB each
- Exact OpenAI tokenization: Uses local o200k_base BPE encoding for precise token counts matching the API
- Provider-calibrated projections: Anthropic, Google, and DeepSeek counts use deterministic UTF-8 projection methods clearly labeled as estimates
- Image token calculation: Applies each provider's published vision rules (tiles, patches, media tokens) based on pixel dimensions read locally
- Live cost estimation: Calculates input costs using current per-million-token pricing with tier-aware pricing for long-context models
- Context window validation: Warns when combined input exceeds model context limits before you make an API call
- Workload & Scaling Planner: Projects per-call, daily, and monthly costs based on expected output tokens and request volume
- Markdown export & sharing: Copy detailed breakdowns or share calculations via URL
- Multi-language support: Available in English, Spanish, Japanese, German, and Portuguese (Brazil)
Target Users
- AI/ML engineers planning model selection and budgeting for production workloads
- Developers integrating LLMs who need to validate context fit before API calls
- Data scientists measuring token costs for document ingestion pipelines
- Product teams comparing provider economics for multimodal applications
- Cost-conscious teams optimizing prompt engineering and batch processing strategies
Unique Selling Points
- True browser-only processing — No server-side token counting, no data collection, no account required
- Transparent methodology — Every result shows its calculation method (exact BPE vs. calibrated projection) and accuracy badge
- Multi-provider comparison — Single input measured across four major providers simultaneously
- Vision model support — One of few tools calculating image tokens using provider-published formulas
- Always current pricing — Registry refreshed from Models.dev with offline fallback
- Developer-first UX — Token inspector, attachment chips, keyboard shortcuts, and copyable Markdown breakdowns
