Tools
Small, deterministic tools that run entirely in your browser. Paste text or pick a sound; nothing leaves the page. Each tool shows its working — the count, the source, the heuristic — so you can see exactly what it did and exactly what it didn't.
An LLM can tell you a story is right for a four-year-old. It rarely tells you why, and almost never shows the math. These tools do the math. Use them next to your LLM, not instead of it — the contrast is the point.
Phoneme inventory analyzer
Paste any text — a target word list, a homework sheet, a chapter book passage — and see what sounds it asks for, by articulation group and acquisition age.
Stimulability quick-check
Pick a sound and an age. Get the typical acquisition window, a few elicitation cues, and a printable word list by position.
ZPD check for AI-generated stories
Paste a story you generated, or one you're considering reading to a child, and get a developmental sanity check against a target age.