All tools
Every tool runs in your browser. Pick a category, or jump straight to a tool.
LLM engineering
Calculators and converters for building with LLMs: token cost, context windows, caching, VRAM, vector size, chunking, tool schemas, JSONL data and rate limits.
LLM Token Cost Calculator
Tokens in, cost per call, per 1,000 calls and per month.
Context Window Checker
Will your prompt, chunks and answer fit the context window?
Prompt Caching Calculator
Cached vs uncached input cost, and the break-even point.
Local LLM VRAM Calculator
Weights + KV cache + overhead, and whether it fits your GPU.
Vector DB Size Calculator
RAM and disk for N vectors at a given precision.
RAG Text Chunker
Split text by characters, tokens or sentences with overlap.
Tool Schema Converter
OpenAI ⇄ Anthropic ⇄ Gemini ⇄ MCP tool definitions.
Fine-tuning JSONL Validator
Line-by-line checks for chat-format training data.
LLM Rate Limit Planner
Max requests per minute, concurrency and queue time.
Data & code conversion
Convert a T-SQL CREATE TABLE statement to PostgreSQL DDL, or turn a JSON sample into Pydantic v2 models. Deterministic, documented rules, no AI and no uploads.