Firefox will slow down the process of loading user tracking scripts

Firefox 57 has just released this month with a secret feature, which is to slow down download script tracking - JavaScript code from user-tracking domains such as ads, analytics or social networks.

Honza Bambas, an engineer at Mozilla in this feature development team, calls it 'tailing'.

Firefox 57 Quantum is here, great Mozilla!

Tailing will speed up page loading

Starting to develop this feature 8 months ago, Bamba said that he had come up with the idea of ranking priority to process the resources needed to load web pages, thereby helping to display the page as quickly as possible, copper. postponing other unnecessary tracking scripts.

'This will improve page loading speed because of saving bandwidth, I / O and CPU to load, process images and scripts on the page,' Bambas said.

These tracking scenarios are not completely blocked but only delayed. Under Firefox's current settings, the tracking script is delayed for up to 6 seconds, after which it will load regardless of whether the site is successfully downloaded.

Tailing against the effective JS tracking

Delaying the monitoring script does not always happen. Firefox will only postpone when they are added as dynamic or asynchronous calls.

By default, the website will load the JavaScript file when calling in sync. But this also does not affect the feature mentioned above because the website now uses the JavaScript library load in parallel (async - async) instead of turn (sync - sync).

Firefox will slow down the process of loading user tracking scripts Picture 1 Firefox will slow down the process of loading user tracking scripts Picture 1
Setup delays user tracking scripts on the page

In addition, most advertising sites load code by calling asynchronously, meaning that this feature will work for most scenarios.

Advertisers and analytics companies are not bothered by this

Surprisingly, slowing down the monitoring script does not make people affected by anger. A web analytics company employee also said it would help them.

'As described, this feature helps them. When everyone put a lot of bookmarks on the page, we had to scramble and even with that page during the download process, so the ranking of the page load is easy to understand ', John Clover, engineer at Heap Analytics said.

Most users complain when tracking code snippets slow down the page loading process. When Mozilla focuses on the necessary code, the page will load faster. Advertising agencies, analysts, don't lose anything but appear more slowly.

At about: config settings page, users can change the first 2 parameters (network.http.tailing.delay-quantum-after-domcontentloaded and network.http.tailing.delay-quantum) to change the delay time. minimum, 3rd parameter (network.http.tailing.delay-max) to change the maximum value and the last parameter (network.http.tailing.enabled) to enable or disable this feature.

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