AI & Data
LLM tokens, test data & probability
Count tokens and estimate API cost for GPT, Claude and Gemini. Paste text, compare models side by side. Runs entirely in your browser.
Turn DAU, requests per user and token sizes into a monthly LLM bill. Compare models on one chart, with prompt caching and multi-turn chat. In-browser.
Paste text and see every token as a coloured block — token IDs, whitespace, chat special tokens, and which characters cost the most. Runs in your browser.
See exactly where your text is split and where chunks really overlap. Recursive and character splitters with real BPE token counts, in your browser.
Generate up to 100,000 rows of realistic fake data as CSV, JSON, NDJSON or SQL. Seeded and reproducible, 100% in your browser. No signup.
Interactive calculator for seven probability distributions. Adjust parameters with sliders and watch the curve, shaded area, probability and quantiles update instantly.
Interactive normal distribution calculator. Drag mean and standard deviation sliders to see the bell curve, shaded probability, z-score and percentile update live.
Convert between z-score, probability and percentile in both directions. Live bell curve with shaded tails, one- and two-tailed critical values, full z table.
Binomial probability calculator with a live bar chart. Exact P(X=k), cumulative, inverse and the normal approximation with continuity correction, for any n and p.