TokenCalculator.dev

TokenCalculator.dev is a privacy-first, 100% browser-based LLM token counter and API cost estimator built for developers, AI engineers, and product teams.

Unlike conventional text-only counters, it processes prompts, local documents (PDF, DOCX, and codebases across 20+ programming languages up to 12 MB), and visual payloads (PNG, JPEG, WebP, GIF) entirely inside your browser.

Key Capabilities:
• 100% Client-Side Privacy: Zero prompts, code snippets, or uploaded files are sent to an external server or stored in a database.
• Multimodal Ingestion: Upload local PDFs and Word documents or calculate visual tile/patch tokens directly from images alongside prompt text.
• Multi-Model Comparison: Instantly compare token footprints, context-window fit, and real-time input costs across OpenAI, Anthropic Claude, Google Gemini, and DeepSeek.
• Accurate & Deterministic: Combines exact client-side o200k_base BPE tokenization with provider-calibrated UTF-8 projections and official vision rules.

Ideal for budgeting RAG pipelines, planning agent workflows, avoiding context window overflows, and preventing unexpected API billing surprises before making production calls.