Whatsit — What's this?

About

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.