Let me start by proclaiming with clarity and sincerity: No, Safari 14 (or any other version of Safari) will not block Google Analytics from loading and running on a website. In the midst of Apple's yearly Worldwide Developers Conference, the company showcased some of the privacy improvements to the upcoming version of the Safari web browser (version 14). In fact, the biggest revelation was the new Privacy Report, which is designed to elucidate how much the browser is working towards mitigating the damage caused by cross-site trackers.
On New Year's Eve 2018, I published an article which instructed how to scrape pages of a site and write the results into Google BigQuery. I considered it to be a cool way to build your own web scraper, as it utilized the power and scale of the Google Cloud platform combined with the flexibility of a headless crawler built on top of Puppeteer. In today's article, I'm revisiting this solution in order to share with you its latest version, which includes a feature that you might find extremely useful when auditing the cookies that are dropped on your site.
Update 17 February 2020: Google Tag Manager's Preview mode cookies have been updated with the necessary flags, so they will not break once SameSite enforcement begins. If you've opened the browser console in Google Chrome (since Chrome 76), you might have seen a bunch of warnings in a yellow background related to something called a SameSite cookie attribute that is either missing or incompletely set for cookies set on external domains.
Updated 1 October 2019 With ITP 2.3 it looks like Safari is reducing the usefulness of localStorage as well, so using that as an alternative fix to persistence issues should not be considered future-proof. this solution should not be considered future-proof. Updated 12 March 2019 with some minor clarifications.. On 21st February 2019, WebKit announced the release of the latest iteration of Safari's Intelligent Tracking Prevention (ITP), known as ITP 2.