also: ブラウザーかくちょうきのう
browser extension; web browser extension
Computing term for a small software module that adds functionality to a web browser.
Installing this browser extension allows you to block ads.
ブラウザ拡張機能の開発にはJavaScriptがよく使われる。
JavaScript is often used for developing browser extensions.
アドオン is a broader term for any add-on software, while ブラウザ拡張機能 specifically refers to browser extensions.
プラグイン is often used for plugins that extend functionality of various applications, not limited to browsers.
Standard kanji-katakana spelling; the shorter ブラウザ is more common in modern usage.
Variant with long vowel marker; less common but still seen.
Compound of ブラウザ (browser) + 拡張機能 (extension function). The term is a direct calque from English 'browser extension'.