Why 15 minutes now saves you months
Every budget decision you make — more on Google, less on Meta, change the agency, pause a campaign — rests on numbers from GA4 and Google Ads. If the numbers are wrong, the decisions are confidently wrong. And tracking breaks often: a theme update, a new plugin, a changed form, a cookie banner installed. Nobody sends you a notification.
The checklist below needs no code. You need: the site in a browser, access to GA4 and Google Ads, your phone and 15 minutes. Run it monthly and after any change to the site.
Preparation (2 minutes)
Open GA4 → Reports → Realtime. This is where you see events as you produce them. Open the site in a private (incognito) window, so you start without old cookies. Accept the cookie banner — we check the "accepted" case first.
The checklist
| # | Check | How to verify in 1–2 minutes | Good sign |
|---|---|---|---|
| 1 | The thank-you page fires once | Submit the real form. In Realtime, count the generate_lead events (or whatever yours is called) | exactly 1 |
| 2 | Phone clicks are counted | On mobile, tap the phone number on the site (you can hang up immediately) | a phone click event appears |
| 3 | The WhatsApp button is tracked | Tap the WhatsApp button | a distinct event appears, not just a generic click |
| 4 | Conversions are not duplicated | Reload the thank-you page | the event does not appear again; if it does, you are counting ghosts |
| 5 | Google Ads ≈ GA4 | Compare the last 30 days: conversions in Google Ads vs Paid Search key events in GA4 | difference under 20–30%, same trend |
| 6 | Consent is respected | New private window, refuse the banner, browse 2 pages | you do not appear in Realtime |
| 7 | Internal traffic is excluded | Ask a colleague to visit from the office | they do not appear in Realtime |
| 8 | UTM links work | Open a link from the newsletter or from a bio | in Realtime, source and medium show the campaign, not Direct |
Where you stand:
- 8 out of 8: rare. Note the date and congratulate yourself.
- 6–7: normal for a well-kept site. Fix what is missing this week.
- Under 5: make no budget decision from the current data until you fix it.
Where it usually breaks
1 and 4 — doubling. The most common problem and the most expensive: once through the old theme, once through GTM. Or the Google Ads tag fires both on the thank-you page load and on the form event. Google Ads learns that each lead costs half of what it really costs and bids accordingly. If reloading at step 4 produces the event again, you also have the classic problem of a directly reachable thank-you page: customers bookmark it, search engines index it, colleagues open it.
2 and 3 — the call and WhatsApp. For many local services, half the customers call or write on WhatsApp. If you only count the form, your "bad" campaign may be the one bringing the calls. Both can be measured as link clicks (tel: and wa.me), nothing complicated.
5 — close, not identical. They will never match exactly: Google Ads places the conversion on the click date, GA4 on the event date; attribution windows differ; Google Ads also sees conversions on another device. What you are looking for is a stable difference. If last month the gap was 15% and now it is 70%, something broke.
6 — does the banner talk? A banner that looks good but sends no consent signals is the most frequent case. If after refusing you see exactly the same events in Realtime as after accepting, the banner is decorative. The Consent Mode v2 lesson explains the fix.
7 — you and your team. On a site with 50 visits a day, five colleagues visiting daily are 10% of traffic, with 0% conversions. GA4 has an internal traffic definition (by IP address) in the data stream settings, and the matching filter must be active, not left in testing mode.
8 — the mysterious Direct. If the newsletter or the Instagram link show up as Direct, every euro spent there is invisible. Every link outside the site gets UTM parameters — utm_source, utm_medium, utm_campaign — written in lowercase, consistently. Newsletter and newsletter are two different sources.
What to do with the result
Problems 1, 4, 7 and 8 are usually fixed from GTM and GA4, without code in the site. Problems 2 and 3 need a new trigger in GTM. Problem 6 needs the banner wired to Consent Mode — the most technical of all. Problem 5 is usually a symptom of the others.
What to remember
- Eight checks, 15 minutes, no code: run them monthly and after any site change.
- Doubled conversions are the most frequent and most expensive mistake — Google Ads bids on false data.
- Calls and WhatsApp can be measured; without them you judge campaigns on forms alone.
- Google Ads and GA4 must be close and stable, not identical.
- Under 5 out of 8: no budget decision until you fix it.
Check yourself
Frequently asked
I see nothing in Realtime although I am on the site. Is it broken?
Check three things: you accepted the banner; you have no active ad blocker in the browser; you are not filtered as internal traffic. If all three are fine and you still do not appear, the GA4 tag is not loading — that is a real problem.
How often should I run the checklist?
Monthly, plus after any update to the theme, plugins, form or cookie banner. Most breakages appear right after such changes.
Want Valhalla to check this for your business?
Valhalla Pulse scans the public signals of your website for free, in seconds.
Sources
Next lesson · in the "Measure everything correctly" path
Google Tag Manager from zero: one container, no code in your siteWhat GTM is and why every site needs one container. Tags, triggers, variables, the data layer explained on a form, Preview, versions, naming conventions and what never goes into GTM.Lesson · 5 min · Beginner · Updated 28 Sept 2026✓Related lessons