Memory footprint of Facebook’s Like button iframes

I have made a rough review of Facebooks Like button memory footprint. Since every like button sits in an iframe I am assuming that this would have a heavy impact on a browsers memory footprint. Web developers should keep that in mind when putting many of them on a single page. Not to mention that each like button comes with it’s own Javascript and CSS files and that Facebook is most certainly tracking even people not using the button and so on and so forth…

There *are* very good reasons not to use Facebook’s Like button regardless of its memory footprint.

The tests were made with Firefox 3.6.10 on Vista with Firebug and some other plugins enabled on a client’s WordPress blog. I have recorded the amount of iframes, peak memory value (the highest value during or shortly after page load) and idle memory value (20-30s after page load).

Keep in mind that this is by no means scientific. YMMV.

Amount iframes ~MB peak ~MB idle
1 105 50
11 108 57
21 125 70
31 149 80
41 175 100

Obviously idle memory footprint scales at about 1,0-1,2 MB per iframe. That is quite a lot.

And do remember that each iframe comes with its

  • own HTML,
  • inline JavaScript,
  • inline CSS,
  • external JavaScript and
  • external CSS and
  • at least one image.

I have not counted the exact amount of requests though I expect ~4, maybe ~5 HTTP requests per Facebook Like button iframe. With 40 of them on one page that sums up to 160 HTTP requests just for the Facebook Like buttons.

From a Green Computing point of view it is quite insane.

My conclusion is if you *really* want to use Like buttons that you do not to put more than a dozen or half a dozen Like buttons on a page.