Cookie deprecation is the shorthand for browsers removing or restricting third party cookies. It has been announced, delayed, re-scoped and partially reversed enough times that plans made against any single announcement have mostly been wasted. What is not in doubt is the direction, and for a small company site the practical consequences arrived long before any formal date.
What actually happened, as opposed to what was announced
Several browsers began blocking third party cookies by default years ago. Others introduced partitioning, which keeps the cookie but scopes it to the site it was set on, and shortened the lifetimes of values written by in-page scripts. The most publicised deprecation timeline changed repeatedly and its final shape moved toward user choice rather than a flat removal. The effect on measurement was already substantial before any of that resolved.
What it means for a small site
Your advertising and attribution numbers are less complete than they used to be and will not recover. Retargeting audiences are smaller. Cross-site frequency capping works less well. If any of those underpin a spend decision, the decision needs a different input rather than a workaround. What does not change is your own first party measurement of your own site, which was never the thing being deprecated.
The workarounds, and which are real
Server side tagging moves where the request comes from and does not remove the need for consent. First party identifiers work and put you squarely in the disclosure conversation. Modelled conversions fill the gap statistically and are only as good as the data feeding the model. Fingerprinting is treated as accessing information on the device, is more intrusive rather than less, and regulators have said so. Choose from the first three deliberately and stay away from the fourth.
What to do now
Nothing urgent, and two things worth doing. Find out which of your measurements depend on third party cookies, so the conversation about the numbers is one you start rather than one you answer. And get the consent gating right, because every one of the replacement techniques depends on data from the visitor, and a site that cannot lawfully collect it has no use for the replacement.
Questions people ask about cookie deprecation
Are third party cookies gone?
Restricted rather than gone, unevenly and by different mechanisms in each browser. Plan for unreliable rather than for absent.
Does deprecation mean I no longer need a banner?
No, and this is the most expensive misreading of it. The storage rule covers anything on the device, and the replacements store more on your own domain rather than less.
Should I move to first party identifiers?
It is a legitimate option with a disclosure cost. If you do it, describe it accurately in the notice rather than treating it as a technical detail.
Will my analytics break?
First party analytics was never the target. What breaks is cross-site attribution, which is a different measurement with a different owner.
Is there a date I should plan around?
There has not been a stable one, which is the practical lesson. Plan against the behaviour you can observe in browsers today.