Guide 186 · Conversions · GA4 + Tag Manager
Key event for newsletter sign-ups in GA4: sign_up, the confirmed subscriber, and the rate
A newsletter sign-up is the content site's key event, and its recommended name is sign_up. The event must fire when the subscription is confirmed, not when the form is shown or the button is clicked, or the count holds people who never joined. This guide marks sign_up, checks it against the email list, and works out the session key event rate for a week.
After the steps, the sign_up key event appears under the Key events tab in Admin, and the standard reports show it within a day. The worked example below gives the count and the rate to expect.
Download the reference: the sign_up key-event reference (JSON) (757 bytes, MD5 2ad75380031f8ee98427602f84d84436). It holds the event name, the counting method, the worked-example figures recomputed for this guide, and the checkpoints that prove the key event is recording. The figures in the file are the same figures shown on this page.
What you need
- Editor access or above at property level in GA4. Marking an event as a key event is a property setting, and the star in the Events table does not appear for a Viewer.
- A sign-up flow that confirms the subscription, such as a double opt-in confirmation or a success page after the form is accepted. The confirmation is the signal.
- A way to count real subscribers for the same week, such as the email list itself. The GA4 count is checked against it, not trusted on its own.
The trace
- Fire sign_up on confirmation, not on display. The event must fire when the subscription is confirmed. A form shown 1,000 times is not 1,000 subscribers, and a button clicked by a bot is not one either.
- Send the event with the recommended name. Use sign_up, the name Google recommends for an account or newsletter registration. A custom name such as newsletter_join collects the same clicks but does not plug into the pre-built reporting that uses the recommended name.
- Confirm it in DebugView before marking it. Open Admin, then Data display, then DebugView, complete a sign-up, and watch sign_up arrive. If it arrives when the form is only displayed, the trigger is on the wrong signal.
- Mark sign_up as a key event. Open Admin, then Data display, then Events, and click the star on the sign_up row. A standard property can mark up to 30 events, and this is the one a content site reports.
- Compare the GA4 count with the email list. In the worked example the week shows 127 sign_up key events and the email list gained 119 confirmed subscribers. The gap of 8 is 8 / 127 = 6.30% of the GA4 count, and it is the sign-ups that never confirmed.
- Work out the session key event rate. The week shows 2,200 sessions and 112 sessions with a sign_up key event, which is 112 / 2,200 = 5.09%. The 127 events came from 112 sessions, so 15 sessions produced more than one sign-up, which usually means a second address from the same household.
Dead ends
DEAD END — FIRING ON THE FORM BEING SHOWN. A sign-up form that loads on every article page will fire thousands of times a week if the trigger is the form display. The event is the confirmation, and nothing else.
DEAD END — COUNTING UNCONFIRMED SIGN-UPS AS SUBSCRIBERS. A double opt-in flow only creates a subscriber when the confirmation link is clicked. The 8-event gap in the worked example is the unconfirmed group, and it is not part of the list.
DEAD END — MARKING sign_up AND FORGETTING THE LIST CHECK. A GA4 count that never meets the email list is a number without a check. Compare the two weekly, and the gap stays small enough to trust.
End state
The sign_up event is the newsletter key event, fired on confirmation and checked against the email list. The week closes at 127 key events from 112 sessions, against 119 confirmed subscribers.
| Figure | Value |
|---|---|
| Sessions in the week | 2,200 |
| sign_up key events | 127 |
| Sessions with a sign_up key event | 112 |
| Session key event rate | 5.09% |
| Confirmed subscribers gained | 119 |
| Gap between GA4 and the email list | 8 |
| Gap as a share of the GA4 count | 6.30% |
The rate is 112 / 2,200 = 5.09% and the gap share is 8 / 127 = 6.30%, both recomputed in Python 3 and rounded to two places. The 127 events came from 112 sessions, so 15 sessions produced more than one sign-up. The figures are a worked example, not a real property.
Sources
- Analytics Help — [GA4] Recommended events — the recommended event names, including generate_lead, sign_up, and purchase
- Analytics Help — About key events — marking an event as a key event, the 30-event limit for a standard property, and 50 for Analytics 360
- Analytics Help — Monitor events in DebugView — watching events with their parameters in DebugView
Checked 11 November 2026. The click paths above are the ones in Google's help pages, read 11 November 2026. The sign_up event is the recommended event name for a registration, and marking it from Admin, then Data display, then Events, are as Google documents them. No step in this guide was run inside a live Analytics property, because Admin needs a Google sign-in and this site does not sign in as anyone. The figures on this page are a worked example recomputed in Python 3 with decimal arithmetic, not numbers from a real property. Google moves menu items without warning; if a path on this page no longer matches, the linked help page is the current map.