AI Tools
Practical calculators for building with large language models: estimate tokens, check prompts against context windows, compare API costs and plan RAG chunking. Everything is calculated locally — no AI API is called.
No tools here match. Search all tools
Tokens & prompts
Words & Characters to Tokens EstimatorConvert word or character counts to LLM tokens — and back.
Context Window CalculatorWill your prompt, documents and history fit a model’s context window?
Chat Context Usage CalculatorHow many chat turns fit before the context window fills up.
AI Token CounterCount tokens for GPT, Claude and Gemini, with context usage and cost.
File Token EstimatorEstimate tokens in text, Markdown, code, CSV and JSON files.
JSONL Token EstimatorValidate JSONL and estimate tokens per line for datasets and batches.
Prompt DiffCompare two prompt versions word by word, with token and cost change.
API costs
RAG & embeddings
Embedding Cost CalculatorOne-time embedding cost, vector count and storage for a document set.
RAG Chunk Count CalculatorNumber of chunks for a corpus at a chunk size and overlap.
Chunk Size CalculatorLargest chunk size that fits your retrieval budget and top-k.
Chunk Overlap CalculatorOverlap tokens, stride and storage overhead for chunking.
Token SplitterSplit long text into token-limited chunks with overlap for LLMs and RAG.