This is part three in a four part series on content blockers in iOS 9. Read part one, part two, and part four.

I grabbed my iPhone 6 plus, all my content blockers, updated my testing site list to add more, and ran the tests while connected to my MacBook to record the total page sizes. This measure has a direct effect on speed, and I believe it is a bit more accurate than pure timing. Either way, here are the results:

As you can see, the abandoned Peace app is the most efficient with data, with an average data savings of 38%. Coming in second is my favorite, 1Blocker, with an average data savings of 36%. In third place is the popular Purify app, with an average savings of 35%. ((Purify updated just before testing, to 1.0.1, with big speed improvements in that update.))

Insights

1. Vivio is shown as adding more data. I don’t know what is going on there, but my hunch is that it is hiding ads and not blocking them. A difference I will get into later. But suffice to say: stay away until I unravel that one.
2. I ran 1Blocker with my custom rules to block The Deck advertising, so if you use their baseline whitelist they would likely tie with Purify.
3. John Gruber likes to talk about how good The Deck ads are, but they still carry a cost. In my testing the Daring Fireball page size is 50% less when blocking The Deck ads. Even though the site itself is minuscule is size, that’s still a difference — it just happens to not be a difference worth worrying about.
4. Since Peace isn’t available, 1Blocker is the fastest app you can buy, as long as you block ads from The Deck.
5. It appears some sites are working to actively block content blocking apps, as the test suite today shows more ads getting through than I had seen over the weekend.
6. Some developers have certainly updated their databases to make the apps faster. This is very good for consumers, and very hard to make good comparisons in articles like this. The target is always moving.
7. Bloomberg is easily the biggest shit show of a site I tested. 13mbs for the article with blockers turned on.
8. The fastest apps realized their speed on big media websites like Washington Post, and Wall Street Journal — not only smaller blogs. Only four content blockers were able to reduce the size of this site — though I left all web font blocking turned off. I like web fonts.

Overall, I still highly recommend 1Blocker as it consistently was fast across the board, whereas Peace was not consistently fast — showing struggles with some international sites I tested. I was glad, and impressed, to see Purify perform well on this test, and that seems like a solid option as well — and it is great to see the improvement jumps they have made.

On a final note: I have stopped publishing the list of test sites (which has grown to 19 sites) — so as to make sure that no developers can game my test suite. I will continue to vary those sites as the particular sites don’t matter as much as the mix and averages.