TLDR: Conversion tracking in GA4 is built around events, with important actions marked as key events (conversions). Unlike Universal Analytics goals, GA4 allows richer data collection through event parameters, enabling deeper insights into user behaviour. Businesses should carefully define what truly matters as a conversion, apply consistent naming conventions, assign values where appropriate, and regularly audit tracking.
What is conversion tracking in GA4?
Conversion tracking in GA4 is about identifying and measuring the most important actions users take on your website. GA4 tracks user behaviour: how people arrive on your site and what they do once they’re there. Conversions are simply specific events that you define as being valuable to your business.
GA4 comes with some predefined conversions. For example, for ecommerce websites, there is a default conversion called purchase. This exists because purchases require additional, structured tracking such as transaction IDs, product line items, quantities, revenue, and more. GA4 is designed to handle this complexity out of the box for online stores.
However, not all websites are ecommerce. That’s where key events come in. A key event could be a newsletter sign-up, a contact form submission, a brochure download, or any other meaningful interaction. These are often referred to as micro-conversions, smaller steps that indicate user intent and contribute toward the main business goal.
Conversions in GA4 can have monetary values assigned to them. Even if there’s no direct sale, assigning a value (for example, £1 or £10 for a newsletter sign-up) helps marketers better understand performance, ROI, and KPIs across channels.
Understanding key events in GA4
GA4 represents a major shift from Universal Analytics in how data is collected. In Universal Analytics, tracking was session-based: a session started when a user landed on the site, and pageviews, events, and goals were layered on top.
In GA4, everything is an event.
- Landing on the site is an event
- Starting a session is an event
- Viewing a page is an event
- Clicking a button is an event
This event-based model gives far more flexibility. Once events are collected and visible in GA4, you can decide which ones matter most by toggling them on as key events (conversions).
Another major improvement is that GA4 allows additional parameters to be sent with events. For example, instead of simply tracking a “newsletter_signup” event, you could also track:
- Where the sign-up occurred (header, footer, popup)
- The type of sign-up (marketing, product updates, offers)
These parameters can later be turned into custom dimensions, allowing you to analyse conversion performance in much more detail, something that required significantly more effort in Universal Analytics.
How to set up conversions in GA4
Setting up conversions in GA4 begins with events.
Some events are automatically collected, such as page views, sessions, and first visits. However, conversions typically require additional setup, either by:
- Using a plugin (common for platforms like Shopify or WooCommerce)
- Implementing tracking via Google Tag Manager
- Adding custom code with a developer
For ecommerce sites, plugins usually handle the full journey:
- Viewing items
- Adding to cart
- Starting checkout
- Completing purchase (conversion)
Only the final purchase is marked as a conversion, while earlier steps remain supporting events in the funnel.
For non-ecommerce or B2B websites, conversions like contact forms often need to be manually configured. Once the event fires and appears in GA4, you can mark it as a conversion by toggling it on. If you already know the event name, GA4 also allows you to pre-define conversions by manually adding the event name, rather than waiting for it to fire.
Naming conventions
Best practice is to follow GA4’s predefined format:
- Lowercase only
- No spaces
- Use underscores
Example: newsletter_signup. Consistency here is critical for clean reporting and integrations.
Recommended key events for businesses
Ecommerce websites
For ecommerce businesses, it’s strongly recommended to use a plugin wherever possible to collect as much structured data as possible. Beyond the purchase conversion itself, valuable additional events are included:
- view_item
- add_to_cart
- begin_checkout
While these events should not be marked as conversions, they form a powerful funnel that shows where users drop off.
Product-level data is especially important:
- Product name
- Product ID
- Category hierarchy
- Brand
- Price, discounts, shipping, and total transaction value
When set up correctly, GA4 allows you to analyse performance by brand, category, or even individual products, helping businesses understand exactly what’s driving revenue. This is a good example of how the additional parameters can be used.
Non-ecommerce / lead-gen websites
For lead-generation sites, recommended key events include:
- Contact form submissions
- Newsletter sign-ups
- Brochure or guide downloads
- Demo or consultation requests
Where possible, assigning values to these conversions helps marketing teams evaluate performance more effectively and align spend with outcomes.
Best practices for GA4 conversion tracking
Firstly, keep it simple. Clearly define the main objective of the site and focus conversions around it. Too many conversions can dilute insight and distort reporting. Create a tracking plan, agree upfront what will be tracked, how it will be tracked, and which events are conversions. This ensures alignment between analysts, developers, and stakeholders.
Regular auditing is essential to maintaining accurate GA4 conversion tracking. At a minimum, tracking should be reviewed quarterly to ensure all events and conversions are still firing correctly, as issues can easily arise without being immediately visible in reporting. An annual review should then take a more strategic view, assessing whether any new user interactions, business goals, or site features should be added to the tracking setup. This is particularly important because website updates, development changes, and platform migrations can unintentionally break existing tracking if they are not carefully monitored.
It is also important to be selective about what is marked as a conversion. High-volume interactions such as product views or general page views should remain as events rather than conversions. Key Events/Conversions are used for attribution purposes; as a result, if you are marking high-volume events as conversions, it is likely to have a 1-2-1 relationship between the session and the conversion, meaning the majority of the conversions will be single-step journeys.
Conversions should only represent actions that indicate real business value and can confidently be linked to marketing performance and spend. Alongside this, any significant site change, including redesigns, new functionality, or migrations to a new platform, should always trigger a full tracking review. This ensures data continuity, protects historical insights, and prevents gaps or inaccuracies in conversion reporting.
Conclusion
GA4 conversion tracking is powerful, but only when it’s set up correctly. By focusing on meaningful key events, using consistent naming conventions, assigning values where appropriate, and regularly auditing performance, businesses can unlock real insight from their analytics.
ASK BOSCO® brings GA4 conversion data together with marketing performance, using our overall website performance report, keeping all your data in one place for easier reporting.
ASK BOSCO® is also introducing a new Shopify–GA4 integration feature in 2026, designed to give ecommerce businesses even clearer visibility over their conversion data. This upcoming feature will map GA4 data directly against Shopify’s native e-commerce data, allowing users to compare transactions, products purchased, revenue, and returns across both platforms.
By blending these two data sources, businesses will be able to see not only how users arrive on the site and interact with products, but also validate how many sales and how much revenue are actually recorded in Shopify. This feature will also help address common tracking limitations in GA4, such as data loss caused by cookie consent or browser behaviour. This will support more accurate auditing, improved confidence in conversion data, and better-informed marketing decisions.
