Features
Opera includes built-in tabbed browsing, ad blocking, fraud protection, a download managerand BitTorrent client, a search bar, and a web feed aggregator. Opera also comes with an e-mailclient called Opera Mail and an IRC chat client built in.[50]
Opera includes a "Speed Dial" feature, which allows the user to add an unlimited number of pages shown in thumbnail form in a page displayed when a new tab is opened. Thumbnailsof the linked pages are automatically generated and used for visual recognition on the Speed Dial. Once set up, this feature allows the user to more easily navigate to the selected web pages.[51]Opera is extensible in a third way via plug-ins, relatively small programs that add specific functions to the browser,[52] and as of Opera 11, third-party extensions. However, Opera limits what plug-ins can do. Additionally, "User JavaScript" may be used to add custom JavaScript to web pages.
Languages and localization
As of 2012 Opera was available[53] in 61 languages and locales: Afrikaans, Azerbaijani, Belarusian,Bengali, Bulgarian, Czech, Chinese (Simplified andTraditional), Croatian, Danish, Dutch, English (UKand US), Estonian, Finnish, French (France andCanadian), West Frisian, Georgian, German, Greek,Hindi, Hungarian, Indonesian, Italian, Japanese,Korean, Lithuanian, Macedonian, Malay, Montenegrin, Norwegian (Nynorsk and Bokmål), Polish,Portuguese (Portugal and Brazil), Punjabi, Romanian, Russian, Scottish Gaelic, Serbian, Slovak,Spanish (Latin America and Spain), Swahili, Swedish, Tagalog, Tamil, Thai, Telugu, Turkish, Ukrainian,Uzbek, Vietnamese and Zulu.Privacy and security
See also: Browser security
Opera has several security features visible to the end user. One is the option to delete private data, such as HTTP cookies, the browsing history, and the cache, with the click of a button. This lets users erase personal data after browsing from a shared computer.[64]When visiting a secure web site, Opera encrypts data using either SSL 3 or TLS.[65][66] It then adds information about the site's security to the address bar. It will also check the web site that is being visited against blacklists for phishing and malware, and warn if it matches any of these lists. This behavior is enabled by default, but the user may opt to not make such checks automatically. If this check is disabled, the user can still check sites individually by opening a Page Info dialog.[67]
The user can protect every saved password stored in Opera with a master password. This prevents malware from accessing those passwords unless the master password is known. Also, Opera does not show saved passwords using password manager unlike Firefox and Chrome.
To catch security flaws and other software bugs before they are exploited or become a serious problem, the Opera Software company maintains a public web form where users can submit bug reports.[68] According to Secunia, a computer security service provider, the mean average of unpatched vulnerabilities in the last 365 days is 0.01. This stands in contrast to Internet Explorer(38.3), Firefox (5.77), and Safari (1.54).[69]
In January 2007, Asa Dotzler of the competing Mozilla Corporation accused the Opera Software company of downplaying information about security vulnerabilities in Opera that were fixed in December 2006. Dotzler claimed that users were not clearly informed of security vulnerabilities present in the previous version of Opera, and thus they would not realize that they needed to upgrade to the latest version or risk being exploited.[70] Opera responded to these accusations the next day.[71]
Standards support
Opera was one of the first browsers to support Cascading Style Sheets (CSS), now a major building block of web design.[72] Today, Opera supports many web standards, including CSS 2.1, HTML 5, XHTML1.1, XHTML Basic, XHTML Mobile Profile, XHTML+Voice, WML 2.0, XSLT, XPath, XSL-FO, ECMAScript 5.1 (JavaScript), DOM 2, XMLHttpRequest, HTTP 1.1, TLS 1.0 (1.1 and 1.2 are supported but disabled by default),[73] Unicode, SVG 1.1 Basic, SVG 1.1 Tiny, GIF89a, JPEG, and full support for PNG, includingalpha transparency.[74] Since version 9, Opera passes the Acid2 test, a test of whether or not a browser properly supports certain web standards. Opera was the second or fourth web browser to pass the test (depending on opinions regarding hiding the scrollbar)[75] and the first Windows browser to do so. Opera 10.5+ achieves a score of 100/100 on the Acid3 test[76] which is primarily focused on DOM and JavaScript standards compliance.On Ecma International's ECMAScript standards conformance Test 262[77] (version 0.7.2), Opera version 11.10 scores 3840/10872. Lower scores are better, as the figure represents the number of failed tests out of the total number of tests. A pre-release build of Opera 12 scores 1/10927 on Test 262,[78] the one failed test being invalid.
On the official CSS 2.1 test suite by standardization organization W3C, Opera's rendering engine Presto passes 89.37% (77.44% out of 86.65%) of covered CSS 2.1 tests.