Whatsit — What's this?

Select anything, right-click, get an instant AI explanation in context. On-device — no account, no cloud, free.

Select any word, right-click, and instantly understand it — explained in the context of what you're actually reading. 100% on-device AI. Free. The same word means different things in different places. Whatsit reads the surrounding paragraph, so: • "Apple" in a recipe → the fruit • "Apple" in tech news → the company • "Stockholm" in a travel guide → the city • "Stockholm" in market news → the stock exchange • "transformer" in an AI paper → the neural network architecture HOW IT WORKS 1. Select a word or phrase on any page 2. Right-click → "What's this?" 3. The answer streams into a small card right at your selection PRIVATE BY ARCHITECTURE Whatsit runs entirely on YOUR device using Chrome's built-in AI (Gemini Nano). It makes zero network requests. No account, no cloud, no tracking, no history kept. What you read stays on your machine — not as a policy promise, but because there is no server to send it to. GREAT FOR • Reading news, papers, or documentation full of unfamiliar terms • Reading in your second language — definitions that fit the sentence, not dictionary guesswork • Anyone who's tired of opening a new tab to Google every odd word REQUIREMENTS Chrome 138+ with on-device AI support (~22 GB free disk and a modern GPU, or 16 GB RAM). The first lookup downloads the model once. Explanations are generated in English. Free. No signup. Select, right-click, understand.