Mouse Dictionary

Name: Mouse Dictionary
Rating: 4.5538 (65 reviews)
Author: wtetsu

Super fast dictionary

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Mouse Dictionary is a lightning-fast dictionary extension for Google Chrome, primarily designed for English-Japanese, Japanese-English, and English-English translations, yet fully supports other languages as well.

Key features include rapid lookup speed, intelligent phrase detection, and the ability to import your own text data for personalized use. The extension offers a customizable viewing experience and works beyond regular web pages — supporting PDFs, YouTube captions, input fields, and textareas. Ideal for language learners and frequent translators who need instant definitions without interrupting their workflow.

Add-on Productivity Education

By:

wtetsu

Daily users:

3,382 -23

Rating:

4.55

(65)

Version:

1.5.13 Last updated: 2022-05-02

Version code:

5397647

Creation date:

2018-09-09

Risk:

Permissions:

storage
unlimitedStorage
activeTab

Size:

3.51MB

URLs:

Website

Full description:

Source:

Firefox Browser Add-ons

Updated:

a day ago

Ranking

# 1,468 ▼ 4

Other rankings

#61 in Language Support ▼ 1

#172 in Search Tools

#261 in Other extensions ▼ 1

#4 in mouse keyword 40 ▲ 1

#8 in dictionary keyword 50

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Other platforms

Mouse Dictionary (v1.7.0)

100,000 4.71

(114)

User reviews

Mouse Dictionary is praised for its speed, convenience, and detailed word explanations, making reading English content efficient and smooth. However, users commonly note that the Firefox version is outdated compared to the Chrome counterpart and suffers from unintuitive setup and usage, especially regarding dictionary imports and activation shortcuts. Clearer indication of active dictionaries and more frequent updates are desired. Despite initial learning curves, it remains a highly valued tool for quick English word look-up.

Pros

Very convenient for quickly checking word meanings, especially while reading tech blogs or manuals.
Almost no waiting time for dictionary look-up, enabling smooth and efficient reading.
Allows reading English sites entirely with single-hand operations when using scroll-enabled mouse or touchpad.
Highly effective and quick for its purpose, showing detailed dictionary entries rather than just translations.
Users praise its high performance and ease of use once set up properly.

Cons

Firefox version lacks recent updates compared to Chrome version, with over a year without update.
Not very intuitive; users report difficulty figuring out how to properly use the add-on initially.
Some users find it difficult to configure or activate dictionaries, especially the English-English dictionary requiring manual import steps.
Lack of clear indication about which dictionary is currently in use can be confusing.
Some confusion about the add-on's functionality and limitations (e.g., not working on certain sites).

Recent reviews

by Yo*****, 2025-06-05

by 远离*****, 2025-04-07

テクノロジーブログをよく読みます。単語がすぐ判ります。localのPDFの単語も判ります。マニュアルを読むときに便利です。

by yo*****, 2025-03-05

View all user reviews ›

Extension safety

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Mouse Dictionary does not require any sensitive permissions.

Risk impact analysis details

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Browser Add-ons, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Mouse Dictionary has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
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