Cookieless analytics, explained

Traditional analytics writes an identifier into a cookie and reads it back on every later request, which is what lets it follow one person across months. Cookieless analytics derives a short-lived, non-reversible key from request properties instead, and rotates it daily.

The result identifies a visit reliably within a day and deliberately cannot be joined across days, sites or devices.

You cannot follow an individual across months, so long attribution windows and per-person profiles are out. If your business depends on multi-touch attribution for paid advertising, cookieless analytics is not a replacement for an ad platform's own reporting.

• No cross-device tracking.
• No individual user profiles or long attribution windows.
• Returning visitors are approximate beyond a day.

What it told us. The two rows it loses are the ones a per-person profile needs. The row it gains is the one most sites lose the largest share of their traffic to, which is why cookieless numbers are usually more complete rather than less.

The trade is usually worth it. Without cookies there is normally nothing to ask consent for, which means no banner, which means no missing visitors. On sites where a large share of people decline the banner, cookieless numbers are more complete than cookie-based ones, not less.

It also removes an entire category of compliance work, and a script that does not need to read storage is smaller and faster.

Not automatically. Consent rules depend on what you store and what else runs on your site, and they differ by country. Cookieless analytics removes the most common reason a banner is required, but it is not legal advice and it does not cover the rest of your stack. Check with your own advisor.

Where that leaves you

For understanding one website, the trade is one-sided: the questions cookieless analytics cannot answer are mostly the ones about individuals, and the questions it answers better are the ones about how many people there were. For advertising attribution across other people's sites, it is not the right tool and nothing here will make it one.