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Flash Activation: Browser Comparison

Each of the major browsers has now implemented a feature where Adobe Flash content does not run by default, but each of the browsers has a slightly different implementation and user interface. This guide will help outline the similarities and differences between browsers so that web developers can provide the best experience. Site authors should also read through the site authoring guide for click-to-activate plugins for guidelines about transitioning away from Flash technologies.

In each browser, the decision to enable Flash is made by users on a per-site basis. When a site attempts to use Flash, the browser will prompt the user in some way and give the user an opportunity to enable Flash for that site.

  Mozilla Firefox Google Chrome Microsoft Edge
Setting Name Ask to activate HTML5 by default Click-to-run
'application/x-shockwave-flash' in navigator.mimeTypes by default when Flash is inactive yes no no
'application/x-shockwave-flash' in navigator.mimeTypes when user enables Flash yes yes yes
<object> with fallback content triggers UI yes, with exceptions no yes
small/hidden Flash triggers additional UI yes no no
Enabling Flash automatically reloads the page no yes yes
Other features related to Flash Domain Blocking Plugin Power Saver Peripheral Content Pause

Each of the browser vendors has a roadmap about the future of Flash and changes to the user experience. The Firefox Flash roadmap includes links to roadmaps and posts from other vendors.

UI Comparison

Mozilla Firefox

In-page UI is displayed when the site attemps to use Flash. An icon also appears on the left side of the location bar. The user can click on the Flash object or the location bar icon to activate Flash.

User have the choice to allow Flash just for the current session, or to remember that choice:

If the Flash element is too small to display in-page UI, Firefox will show an alternate information bar which allows users to activate Flash:

Google Chrome

In-page UI is displayed when the site attempts to use Flash without fallback content.

A user can click the plugin element to show a prompt for allowing Flash.

If the site provides fallback content for an object element, Chrome will display that content and will not prompt the user to enable Flash. If a Flash element is not visible to the user, the user will have no visible prompt. On any site, a user can click the information icon on the left side of the location bar to open site information and allow Flash on that site.

Microsoft Edge

In-page UI is displayed when the site attemps to use Flash. An icon also appears on the right side of the location bar. The user can click on the Flash object to show activation options.

User have the choice to allow Flash just for the current session, or to remember that choice:

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 Contributors to this page: bsmedberg
 Last updated by: bsmedberg,