Translated widget text is available in 34 of the languages supported by Twitter.com.
Table: Languages supported by Twitter for Websites widgets and buttons
<a class="twitter-share-button" href="https://twitter.com/share" data-lang="es"> Twittear </a>
Twitter for Websites will extract the most appropriate language from its position in the DOM tree, if no language is provided in the widget markup. Pages which define an unsupported script or region will be mapped to the closest available language: e.g. pt-BR will use pt if Portuguese is available but a Brazilian regional localization is not.
United States English is the default if a page’s language code does not match any available translation.
Setting the language only affects the language of Twitter elements such as action text and timestamp display; Tweet text is always displayed in its originally authored language.
We support all browsers and webviews that support ECMAScript Level 5 and above – this should include all modern browsers and webviews. We build and test our widgets on all modern desktop, and mobile browsers, as well as mobile webviews.
The only exceptions where we do not render are browsers that do not support ECMAScript level 5, and Internet Explorer 11 and below.