Estimate token count and API costs for Claude 3.7, GPT-4o, and Gemini 2.0.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Paste or type the text you want to evaluate.
Choose GPT-4o / GPT-4, Claude 3.5, Gemini 1.5, or Llama 3 tokenizers.
View real-time token counts, character lengths, and estimated API inference costs.
Counts use deterministic BPE tokenizer heuristics modeled after official Byte-Pair Encoding specifications.
No, token counting runs entirely in your browser using local JavaScript computation.
Zero-egress companion tools in the AI Utilities suite
Calculate API inference cost given prompt and completion token counts.
Structure complex prompts using Claude-compliant XML encapsulation tags.
Design sequential multi-step prompt chains (Extraction -> Verification -> Summarization).
Generate systematic Prompt Eval test case matrices in JSON format for automated benchmark suites.
