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A faster, simpler, and safer browser goes polyglot

Wednesday, March 17, 2010 | 10:30 AM

If you're excited about the latest in integrating translation tools into your web experience, today's new stable release of Google Chrome brings to our users translation capabilities in the web browser. Here's quick demo on how the translation feature works in Chrome:

When the language of the webpage you're viewing is different from your preferred language setting, Chrome will display an infobar asking if you'd like the page to be translated for you, using Google Translate. With just a click, the entire text on the page will be translated into your language of preference, without the need for browser extensions or plugins. If you don't want Chrome to offer to translate a particular language or web page, you can control these settings by clicking on the "Options" button in the infobar.

So how does the browser actually 'know' what language the page is in? Language detection takes place locally on your computer, so no information is sent to Google Translate until you choose to translate a page. Language detection in Chrome is based on the compact language detection library (CLD), which we've made available as open source code.

For those of you who are interested in the technical nitty-gritty, here's what takes place under the hood: for most languages, the CLD determines the language of a page by breaking down its text in quadgrams, or sequences of up to four characters. The CLD then looks up each quadgram in a large hashtable that contains language probabilities, which is included in the Chrome binaries. This hashtable was originally built by processing language probabilities over billions of web pages that are indexed by Google's search engine. In just a few milliseconds, the CLD can accurately determine the language of most web pages. Chrome shows an infobar offering to translate the page only when the CLD has detected the language of a web page above a certain degree of confidence. If you click the "Translate" button in the infobar, the text contained in the page is then sent to Google Translate's servers (over a secure connection if the page was served over HTTPS). Thanks to the work of the Google Translate team, Google Translate's servers return this translated text quickly so that Chrome can replace the text in the page with the translated version. Rest assured, the request to Google Translate's servers does not include any cookies.

We're excited to introduce translation in the browser, and look forward to improving this feature over future releases of Chrome. For example, we hope to work on include making language detection even more precise -- by providing larger CLD tables without increasing the size of the browser's installation package, and improving the way Chrome interacts with other website translation tools.

With this new stable release of Chrome, you can easily read a diversity of foreign language information sources, access educational materials from universities around the world, and even conduct online commerce across borders and languages -- all in your native language. We hope that the browser can truly be a passport to a web that is remarkably local as it is global. You can try translation in the browser for yourself by downloading Google Chrome at For those of you who aren't yet acquainted with Chrome, you can learn more about Chrome's speedsecurity, and many other features.

Posted by Jay Civelli, Software Engineer, Google Chrome