Blog
When GA4 is quietly wrong
GA4 does not raise an error when it is configured wrong. These are the problems we meet most often in real scans, written as symptom → cause → how to check in GA4 → how to fix. The code on each post (CV-03, for example) is its number among the thirty checks AnalyticScan runs.
3 November 2026·5 min read
You have just inherited a GA4 property — seven checks for week one
No handover document, just the account. Week one is not for changing settings, it is for finding out what is being collected and what is not. Seven checks, in order, all of them read-only.
GA4GuideData qualityCV-01CV-02EV-01EV-05PR-0429 October 2026·3 min read
The two-month retention trap — why only Explorations come up empty
Standard reports happily show last year, but the same period in an exploration is blank. GA4 keeps event-level data for two months by default, and once it is deleted no setting brings it back. A one-minute change that gets more expensive every month you leave it.
GA4SettingsData qualityST-0129 October 2026·4 min read
The 500-event limit does not apply to web — cleaning up zombie events
Your event list runs past 200 rows and most of them fired a handful of times in 28 days. The 500 limit belongs to app streams, not web. Why the list is still worth cleaning, and how to tell which events are safe to remove.
GA4Event collectionData qualityEV-05EV-0427 October 2026·4 min read
When development and staging traffic mixes into production
Hostname shows localhost and vercel.app, and sessions spike only on release days. When development shares a measurement ID with production, the checkout flow your QA team walked lands in your revenue. Why the volume matters less than the shape, and how to separate environments.
GA4GTMSettingsTG-0227 October 2026·4 min read
Event naming rules — snake_case, reserved names, non-English names
Your event list has Purchase and purchase in it, a name with a space, and one written in Korean. What GA4 actually forbids, what it merely does not recommend, and what you give up when you rename an event that already has history.
GA4Event collectionData qualityEV-0222 October 2026·5 min read
The internal traffic filter is on and the reports have not changed
You registered the office IP and the setting is saved, yet staff sessions are still in the reports. Excluding internal traffic takes two steps, and a filter left in testing removes nothing. How to find where it broke, and why this is a check a person has to make.
GA4SettingsData qualityST-0322 October 2026·4 min read
When email addresses and phone numbers end up in your URLs
Rows with an @ in them appear in your page path report. Google's policy says that data should never have been sent, and GA4 raises no warning. How to find it, how to stop collecting it, and how to delete what already arrived.
GA4Data qualitySettingsPR-0420 October 2026·4 min read
When data thresholds hide your rows — the Google signals trade-off
Your demographics report is nearly empty and the user totals do not match your other reports. GA4 withholds rows to stop individuals being identified, and the data that triggers it is what Google signals brings in. What you gain and what you give up, side by side.
GA4SettingsData qualityST-0515 October 2026·3 min read
When conversions do not match your order count — key event counting
A hundred orders in your own system, eighty conversions in GA4. The cause may be how the events are counted rather than whether they are collected. What once per event and once per session do to revenue and lead events, and where to change it.
GA4ConversionsKey eventsCV-04ST-0213 October 2026·3 min read
The parameter is being sent but the report cannot see it
DebugView shows the value arriving, yet the name is nowhere in the report's dimension list. In GA4, collecting a parameter and reporting on it are two separate switches. How to register one, and how to tell registration problems from empty values.
GA4Event collectionSettingsPR-01PR-028 October 2026·3 min read
When purchase outnumbers begin_checkout — an inverted funnel
More purchases than checkouts gives you a funnel step converting at over 100%. An inverted number is usually evidence of a duplicated purchase event or a missing upper step. Four causes, how to tell them apart, and what to fix in each.
GA4EcommerceConversionsCV-05EV-066 October 2026·3 min read
When an (other) row appears in your reports — cardinality limits
Expand a dimension and one (other) row is holding a large number you cannot open. GA4 collapses the rest once a day's distinct values exceed the limit. What the offending values look like, and how to cut the variety at collection time.
GA4Data qualityEvent collectionPR-03PR-0415 September 2026·3 min read
Registered as a key event, still reporting zero
The event is right there in your key events list and the conversion count has been zero for a month. Why flipping the toggle is not the same as firing the event, and the order of checks that narrows the cause in half an hour.
GA4ConversionsKey eventsCV-02CV-0114 September 2026·3 min read
Duplicate events: when page_view counts twice
Pageviews per session sitting at 2 and an implausibly low bounce rate mean the same action is being counted twice. How to find a double GA4 install or an overlap with Enhanced Measurement, and clean it up.
GA4GTMEvent collectionEV-01EV-0313 September 2026·2 min read
When purchase has no value or currency, and ROAS never appears
Purchase counts arrive but revenue reads zero and ROAS is blank in your ad reports. Why GA4 refuses to calculate the money, and how to confirm and fix it in DebugView in five minutes.
GA4EcommerceConversionsCV-03PR-057 September 2026·5 min read
7 things that make GA4 data untrustworthy
Conversions counted as zero, ROAS that will not calculate, staging traffic in production. The seven GA4 problems we find most often, with how to check and fix each one.
GA4Data qualityGuideCV-02CV-03TG-02EV-01EV-04ST-01PR-04