[tbb-dev] reconsider shipping uBO or enabling ETP?

gunes acar gunes.acar at esat.kuleuven.be
Wed Jul 1 16:16:19 UTC 2020

Hi all,

I was wondering if Tor Browser team is open to reconsider shipping an
adblocker or turning on Firefox's Enhanced Tracking Protection (ETP)
mode, and whether you need some research input that may inform that

I am aware of issue #17569 and I agree with most of the arguments laid
out in the "No filters" part of the design doc. Especially that the
list-based approaches would not improve TB's existing privacy
protections with respect to curtailing online tracking.

However, tracking protection/adlocking also have significant performance
benefits [1, 2], which is the main reason why I'm bringing this up.

Just to find out whether there could be potential performance benefits
of shipping uBO with TB, I did a quick crawl of sites from the Trexa
list [3] using TB with and without uBlock Origin (uBO) installed. Having
uBO *reduced the median page load time by 27.6%* (from 7.6s to 5.5s) on
top 1K sites. You can imagine there would be a similar reduction in the
network footprint due to blocked requests.

Another reason why it may be timely to reconsider this issue is that
today all major browsers except Chrome ship a built-in adblocker or
tracking protection mode (Safari, Firefox, Edge, Opera, Brave...). So,
Tor Project may not really stand out for "damag[ing] the acceptance of
Tor users by sites"[4] by blocking ads.

I and some colleagues could be interested in dedicating some research
time into studying the potential privacy and performance impact of
adding adblockers or enabling ETP mode -- esp. if the JIT issue (#23719)
makes uBO and other addons infeasible.

Can you let us know if there's willingness to reconsider shipping an
adblocker/ETP, and if so what research may help you with your decision?


[2] https://dl.acm.org/doi/pdf/10.1145/3366423.3380292
[3] https://github.com/mozilla/trexa
[4] https://2019.www.torproject.org/projects/torbrowser/design/#philosophy

More information about the tbb-dev mailing list