- Language: Deutsch (German)- Firefox Language Pack for Deutsch (de) – German - 1,200,699 users
- Language: Français (French)- Firefox Language Pack for Français (fr) – French - 1,143,936 users
- Facebook Container- Prevent Facebook from tracking you around the web. The Facebook Container extension for Firefox helps you take control and isolate your web activity from Facebook. - 872,834 users
- Tampermonkey- Tampermonkey is the world's most popular userscript manager. - 777,280 users
- Language: Español (ES) (Spanish, Spain)- Firefox Language Pack for Español (ES) (es-ES) – Spanish, Spain - 766,362 users
- Cisco Webex Extension- Join Webex meetings using Firefox ™ - 630,496 users
- Grammarly: AI Writing and Grammar Checker App- From blank page to polished draft, Grammarly’s AI helps you write faster and stronger. Get real-time grammar fixes, tone transformations, and instant content generation right where you write in Firefox. - 624,252 users
- IDM Integration Module- Download files with Internet Download Manager - 620,187 users
- Language: Português (BR)- Firefox Language Pack for Português (BR) (pt-BR) – Brazilian Portuguese - 593,161 users
- Language: Español (MX) (Spanish, Mexico)- Firefox Language Pack for Español (MX) (es-MX) – Spanish, Mexico - 587,989 users
- Language: Русский (Russian)- Firefox Language Pack for Русский (ru) – Russian - 571,588 users
- Capital One Shopping: Save Now- Capital One Shopping instantly applies coupon codes to your shopping cart, helps you snag exclusive rewards when you shop at stores you love and compares prices on Amazon to other popular retailers. It's kinda genius. - 493,969 users
- Browsec VPN - Free VPN for Firefox- Unblock geographically restricted content and protect your IP with Browsec’s add-on. With this Firefox VPN extension, you can stay anonymous for an unlimited time! Use free remote servers to hide your location and access any content you want. - 490,512 users
- Language: Polski (Polish)- Firefox Language Pack for Polski (pl) – Polish - 464,561 users
- Malwarebytes Browser Guard- The fastest and safest web browsing experience. Secure your privacy by blocking trackers, blocking ads, and blocking malicious content. - 448,836 users
- LastPass Password Manager- LastPass, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device. - 439,342 users
- 434,952 users
- Norton Safe Web- Protects your browser from online threats. - 424,357 users
- SaveFrom.net helper all-in-1 / youtube downloader- SaveFrom.net helper will enable you to download files from YouTube.com, FaceBook.com, Vimeo.com, Daylimotion.com, VK.com, Odnoklassniki.ru, Soundcloud.com and more than 40 other just in one click. - 393,826 users
- Language: Italiano (Italian)- Firefox Language Pack for Italiano (it) – Italian - 389,872 users
- Firefox Multi-Account Containers- Firefox Multi-Account Containers lets you keep parts of your online life separated into color-coded tabs. Cookies are separated by container, allowing you to use the web with multiple accounts and integrate Mozilla VPN for an extra layer of privacy. - 385,109 users
- Language: Español (AR) (Spanish, Argentina)- Firefox Language Pack for Español (AR) (es-AR) – Spanish, Argentina - 381,144 users
- Honey- Automatically find and try coupon codes with 1-click. Works at thousands of stores in the US, Canada, Australia, India and the UK. - 372,987 users
- Language: 简体中文 (Simplified Chinese)- Firefox Language Pack for 简体中文 (zh-CN) – Simplified Chinese - 363,339 users
- Kaspersky Protection 2021- Your protection on the Internet with extension from Kaspersky Lab - 362,651 users
















