Google Analytics 4 annotations: where to find them and where they fall short

For years, the most common complaint about Google Analytics 4 was that it dropped a feature Universal Analytics had: annotations, the little notes you could pin to a date so future-you remembered what happened. Google added them back, and they are genuinely useful. They are also limited in ways worth understanding before you lean on them.

I spent a lot of years living inside analytics dashboards. Annotations were the difference between "traffic dropped on the 14th" and "traffic dropped on the 14th because we relaunched the homepage". Here is how to use them in GA4, and where they stop being enough.

Where to find annotations in GA4

Annotations live on the time-series charts inside your GA4 reports. When you hover over the chart, you can add a note tied to a specific date, and any annotation on that date shows up as a marker under the line.

1. Open a report with a time-series chart

   Most standard reports (Reports, then Acquisition or Engagement) show a line chart over time at the top.

2. Add an annotation on the chart

   Use the annotation control on the chart to create a new note. You set the date, write a short description, and save.

3. Choose who can see it

   You can keep an annotation private to you or share it with everyone who has access to the property.

Where GA4 annotations fall short

They are a real improvement, but they solve a small part of the problem. Four limits show up fast in real work:

• They only live inside GA4. The deploy that caused the drop happened in GitHub. The campaign launched in Google Ads. The tag change happened in Tag Manager. None of that is in GA4, so you are still annotating by hand, after the fact, from memory.
• Someone has to remember. An annotation only exists if a human stops, opens the chart, and types it in on the right day. The events you most need to remember six months later are exactly the ones nobody had time to log in the moment.
• They do not cross tools. Your traffic story is spread across analytics, ads, search, deploys, and your CMS. GA4 annotations cover one of those surfaces. To see the full picture you would annotate the same event in several tools, which nobody does.
• They are easy to lose. Annotations sit behind a chart most of your team never opens. They are not a shared, searchable record the whole company can read when a number moves.

What actually answers "why did the numbers move?"

GA4 annotations are worth using. Turn them on, add them for the big moments, share them with your team. But treat them as one note pinned to one chart, not as your company's memory.

What you really want is the opposite of manual annotation: a record that fills itself. Connect the tools where change actually happens, deploys, tag manager, ad platforms, your CMS, and let each one log its own events automatically onto one shared timeline. Then when GA4 shows a dip, you do not reconstruct the week from memory. You open the timeline, find the date, and the deploy, the campaign, and the config change are already there, side by side.

That is what CoNote does. GA4 tells you the number moved. CoNote tells you why.