How to Disable or Customize Alert Box Animation in Mozilla Firefox and Thunderbird?

If you are a Mozilla Firefox or Thunderbird user, you might be aware of the small alert box which appears in the bottom-right corner of screen whenever a download finishes or a new email arrives.

The alert box is shown using a smooth sliding animation. It stays for a few seconds and disappears. It looks like following screenshot:

Although the animation looks cool but sometimes it causes weird problems in specific situations like when you are playing a game or watching a movie.

In this tutorial, we’ll tell you how to disable the animation permanently or how to customize the animation according to your requirements.

So without wasting time, lets start the tutorial:

1. Mozilla Firefox users will need to type about:config in the addressbar and press Enter. Thunderbird users will need to go to Tools -> Options -> Advanced menu and then click on “Config Editor” button.

[Tip] How to Access “About:Config” Page in Mozilla Thunderbird

It’ll confirm, click on I’ll be careful, I promise! button.

2. Now type alerts in the Filter box and you’ll see following preferences:

3. You’ll need to change the values of above mentioned preferences to disable or customize alert box animation.

• alerts.totalOpenTime – This preference is responsible for the time that the alert box remains open.
• alerts.slideIncrementTime – This preference defines time which is taken by animation to perform a slide.
• alerts.slideIncrement – This preference defines the number of pixels to slide per animation.
• alerts.disableSlidingEffect – This preference allows you to disable / enable the animation.

By default, alerts.totalOpenTime is set to 4000 which means 4 seconds, alerts.slideIncrementTime is set to 10 in Firefox and 50 in Thunderbird, alerts.slideIncrement is set to 1 and alerts.disableSlidingEffect is set to false.

4. To disable the animation, you just need to set alerts.disableSlidingEffect to true. Double-click on it or right-click on it and select “Toggle“. It’ll set its value to true.

5. If you don’t want to disable the animation but want to customize it, then you’ll need to change values of the other 3 preferences according to your requirements.

You can set the values to any positive integer. We tested and found following values optimal:

You can play around the values and set which suites better to your requirements.

Also Check:

[Tip] Make Mozilla Firefox Faster by Disabling UI Animations