February 2020: Chrome tightens SameSite cookie rules and tracking takes a hit
Covers February 2020. Part of our search timeline: a month-by-month look at the changes that shaped SEO, AI search, paid ads and social media, written in November 2026 for local businesses with the benefit of hindsight.
Quick answer: From February 2020, Chrome started to treat any cookie with no SameSite setting as first-party only unless told otherwise. Certain embedded tools, payment journeys and tracking that worked across sites stopped behaving until they were fixed. It was the first major move in the long shift away from third-party cookies.
For a local service business, the effect was usually hidden. A roofer paying for Google Ads or a cleaning company using an embedded booking widget might simply have seen fewer conversions reported, with no obvious reason why.
What changed in February 2020?
Chrome 80 switched the default cookie behaviour. Any cookie meant to work across different sites now had to be marked explicitly as SameSite=None and Secure. Cookies without that setting could only be used by the site that created them.
Why did it affect UK businesses?
Ad tags, affiliate links and certain embedded checkouts all needed cookies that worked across sites. Where the tools had not been updated, conversion data went missing, and that changed how the ad platforms optimised campaigns. If an ad platform cannot see which clicks turned into booked jobs, it has less to learn from.
What to do about it now
- Rely on first-party measurement where possible, for example server-side tagging and analytics that is set up properly.
- Test conversion tracking after every website or tag change, not only on launch day.
- Keep a list of the tags that rely on cookies so you can respond quickly when browsers change their rules.
Frequently asked questions
What is a SameSite cookie?
It is a setting on a cookie that controls whether the browser can send it along with requests that start on another site. It helps protect people from cross-site attacks.
Did this change get rid of third-party cookies?
No, it tightened the rules. Chrome later abandoned its plan to remove third-party cookies completely, but privacy restrictions have continued to grow.
Sources and further reading
Want help with this? Our analytics and measurement service checks that your enquiries and bookings are being tracked properly. Get in touch.
More articles
May 2020: Core Web Vitals are announced by Google
Google introduced Core Web Vitals in May 2020 as part of page experience. What they measure, how they changed, and what local firms should check now.
November 2020: a launch date for page experience and a new Crawl Stats report
In November 2020 Google set a date for its page experience update and relaunched Crawl Stats in Search Console. How local firms can use both now.
June 2021: Google begins rolling out the page experience update
In June 2021 Google started rolling out page experience and Core Web Vitals as ranking signals, plus a core update. What it meant for trades.