Here is an incomplete list of browsers that are known to work well with Drupal 7 core and support all of its features:
- Internet Explorer 6.x and later
- Firefox 5.x and later
- Opera 12 and later
- Safari 5.x and later
- Google Chrome
IE8 and older has a problem with loading more than 31 stylesheets, a situation that may be encountered if you are using a contributed theme or number of contributed modules. An acceptable workaround is to enable CSS aggregation.