Cá»Âc Cá»Âc browser (; meaning "knock knock" and previously Cá» Rôm+ ; ) is a freeware web browser focused on the Vietnamese market, developed by Vietnamese company Coc Coc Company Ltd and based on Chromium open source code. Cá»Âc Cá»Âc is available for Windows, Windows Phone, Android, and macOS operating systems and supports both English and Vietnamese. Cá»Âc Cá»Âc also has .
Cá»Âc Cá»Âc was founded in 2008 as iTim Technologies LLC by Victor Lavrenko, a Soviet-born Israeli entrepreneur, the founding CTO of Mail.ru, and founder and CEO of the Russian search engine Nigma, along with Vietnamese co-founders Lê VÃÂn Thanh, Nguyá» n Thanh Bình, and Nguyá» n ÃÂức Ngá»Âc. Lavrenko leveraged his experience from Mail.ru and , with the initial ambition of dominating the Vietnamese market as a search engine. The Vietnamese co-founders concentrated on developing Vietnamese language-related features, including algorithm improvements, product management, and operational functions.
Two months after the official release, the number of Cá»Âc Cá»Âc users in Vietnam surpassed Opera and later Safari and Internet Explorer.
On 2 April 2014, Cá» Rôm+ was officially re-branded as the Cá»Âc Cá»Âc browser to unify the company's brands under that name: Cá»Âc Cá»Âc Search Engine, Cá»Âc Cá»Âc browser and NhàNhàmobile app.
In October 2017, Cá»Âc Cá»Âc reached more than 22 million users and ranked as the second most popular browser in Vietnam after Google Chrome.
Cá»Âc Cá»Âc has a mechanism to perform reverse domain name resolution, allowing the bypassing of blocked websites (including Facebook) on DNS. This feature debuted on 14 May 2013, in the first official release of the browser.
Cá»Âc Cá»Âc is equipped with a system that automatically adds lingual tone to Vietnamese text. It allows the user to enter Vietnamese text without the need for applications like Unikey, EVkey and Vietkey. When users type any text without tone, Cá»Âc Cá»Âc will suggest the most likely variants of tone arrangements, once processed on the Cá»Âc Cá»Âc server. Cá»Âc Cá»Âc also incorporates an English-Vietnamese dictionary, assisting English learners or international newspaper subscribers from elementary to the advanced level. When users double click on any English word, a small box will appear on site, showing meaning and pronunciation of the word.
Cá»Âc Cá»Âc is able to find media content on most streaming websites and save it to the computer for viewing or listening offline by clicking on an icon in the toolbar. Except for several premium websites, all popular streaming websites such as YouTube and Dailymotion are downloadable on the browser.
In November 2014, Cá»Âc Cá»Âc surpassed the Firefox browser in desktop usage, becoming the second most popular browser in Vietnam with a market share of 18.25%.
On August 2017, Cá»Âc Cá»Âc reached its peak market share in desktop usage, achieving 32.54%. However, its market share began to decline thereafter. By August 2020, its share had dropped to 16.42%.
As of August 2024, the desktop market share of Cá»Âc Cá»Âc was recorded at 11.41%.
By November 2024, the combined market share of Cá»Âc Cá»Âc across all platforms (desktop, mobile, and others) had fallen to 3.67%, while Google Chrome dominated the Vietnamese browser market with a 64.44% share.