
With ABP, that number more than doubles, to 417 MiB. For example, if I load TechCrunch and roll over the social buttons on every story (thus triggering the loading of lots of extra JS code), without ABP, Firefox uses about 194 MiB of physical memory. Many pages have multiple iframes, so this can add up quickly. Second, there’s an overhead of about 4 MiB per iframe, which is mostly due to ABP injecting a giant stylesheet into every iframe. (This is on 64-bit builds on 32-bit builds the number is probably a bit smaller.) This appears to be mostly due to additional JavaScript memory usage, though there’s also some due to extra layout memory. Mozilla developer Nicolas Nethercote explains why ABP is so CPU- and memory-intensive:įirst, there’s a constant overhead just from enabling ABP of something like 60–70 MiB.

But its ad-blocking benefits come with a price: very high CPU and memory usage, which could be a big problem if you're surfing around on a computer without high-end resources. AdBlock Plus is the most popular extension for Mozilla Firefox and Google Chrome.
