TokenCalculator.dev

TokenCalculator.dev is a privacy-first, browser-based token calculator designed for developers, AI engineers, and teams working with large language models. It enables users to count tokens in text, PDFs, DOCX files, source code, structured data files, and images entirely within the browser, so no prompts or documents ever leave the device. The platform provides live token and cost estimates for OpenAI, Anthropic Claude, Google Gemini, and DeepSeek, with a clear accuracy contract that distinguishes exact OpenAI o200k_base BPE tokenization from deterministic Provider-Calibrated UTF-8 Token Projections. It also includes a tokens-to-words converter, a Cost Lab for model pricing and batch projections, focused provider calculators, workflow field notes, and current model comparisons. The user experience is clean and transparent, featuring live provider cards, context-fit warnings, and methodology pages. Technical features include local file parsing, image-token formulas, an API reference, integrations, and an offline pricing registry. This makes TokenCalculator.dev essential for estimating API costs, planning context windows, comparing models, and protecting sensitive data.