Google Analytics 4 is event-driven, all data and behaviors are tracked through events, but event tracking also has some limitations.
|Distinctly named events
|Events per User per day
Event = Event name + Event parameter
Length of event name is up to 40 characters.
Event parameters per event is up to 25, since there are 5 default event parameters, actually 20 can be set.
Event parameters are divided into Event Scope Custom Dimension and Event Scope Custom Metrics.
Event Scope Custom Dimension is up to 40 characters.
Event Scope Custom Metrics is up to 100 characters.
Events can be divided into four types:
Automatically Collected Events
Automatically Collected Events (aka Automatic Events) are automatically collected by the system without additional settings, as long as you have the gtag.js installed, and basic user interactions with your website, for example: page_view.
Automatically Collected Events include:
- first_visit： the first time a user visits a website
- page_view：each time the page loads or the browser history state is changed by the active site
- session_start：when a user engages the website, A session ID and session number are generated automatically with each session and associated with each event in the session
- user_engagement：when the app is in the foreground or webpage is in focus for at least one second
Automatically Collected Events cannot be disabled, and do not count towards the 500 event limit.
Enhanced Measurement Events
Enhanced Measurement Events are built-in events, just need to be enabled in the web data stream, No code changes are required, and Google Analytics tag starts sending events right away.
Enhanced Measurement Events include 6 type :
Enhanced Measurement Events
|each time the page loads or the browser history state is changed by the active site
This event is collected automatically. You cannot turn off collection.
|the first time a user reaches the bottom of each page (i.e., when a 90% vertical depth becomes visible)
|each time a user clicks a link that leads away from the current domain
By default, outbound click events will occur for all links leading away from the current domain. Links to domains configured for cross-domain measurement will not trigger outbound click events.
|each time a user performs a site search, indicated by the presence of a URL query parameter
By default, the event is triggered based on the presence of one of the following 5 parameters(q、s、search、query、keyword) in the URL，you can customize up to 10 parameters
|search_term, optionally ‘q_<additional key=””>’ (where <additional key=””> matches an additional query parameter you specify to be collected under advanced settings)
|For embedded videos that have JS API support enabled, the following events are triggered:
|Triggered when the user downloads the following file: pdf|xlsx?|docx?|txt|rtf|csv|exe|key|pp(s|t|tx)|7z|pkg|rar|gz|zip|avi|mov|mp4|mpe?g|wmv|midi?|mp3|wav|wma
Recommended Events is Google’s pre-defined event name and event parameters based on the industry. You need to send data according to the predefined event name and event parameters before you can see the data in GA4.