Key features
- hover-triggered pop-up word definitions
- customizable dictionary data and display settings
- built for speed on text-heavy pages
- no account required to use
What Mouse Dictionary does
Mouse Dictionary shows a definition pop-up as you move your cursor over a word, without needing to click, select text, or open a new tab. It's designed for language learners who read a lot of text in a language they're studying and want the fastest possible way to check unfamiliar words mid-sentence.
Mouse Dictionary free vs paid
The extension is free with no listed paid tier. Because it's customizable, some of the setup — like importing a specific dictionary dataset — takes more effort than plug-and-play tools, but there's no cost involved in unlocking that customization.
Is Mouse Dictionary safe?
To show hover definitions, the extension needs to read the text content of pages you visit, which is necessary for the core feature. It's a focused lookup tool rather than one that collects or shares personal data beyond what's needed to detect the word under your cursor.