⚡ TL;DR: In March 2024, Google renamed "conversions" to "key events" in GA4. Key events are the actions that matter most to your business — form submissions, purchases, sign-ups. The term "conversions" now only applies when data is shared with Google Ads. This guide explains the difference, shows you how to set up key events, and helps you track what actually matters.

What are key events in GA4?

If you've logged into Google Analytics 4 recently and wondered where your conversions went, you're not alone. In March 2024, Google made a terminology change that confused millions of analysts, marketers, and business owners overnight: conversions in GA4 were renamed to key events. Once you've set up your key events, Meaning's GA4 AI chatbot makes it easy to ask questions about your conversion data in plain English — no complex Explorations needed.

But here's the thing — nothing actually changed in how the data works. The same tracking, the same reports, the same underlying logic. Google simply split the terminology to reduce confusion between GA4 and Google Ads.

A key event is any GA4 event that you've marked as important to your business. When a user completes one of these actions — submitting a contact form, making a purchase, signing up for a newsletter — GA4 records it as a key event.

Think of it this way: GA4 tracks hundreds of events automatically (page views, scrolls, clicks). Key events are the ones you've flagged as "this one actually matters to my bottom line."

Key events vs conversions: what changed and why

This is where most people get tripped up, so let's be crystal clear.

Key Takeaway: "Key events" live in GA4 and measure on-site behaviour. "Conversions" live in Google Ads and drive campaign optimisation. They are not interchangeable terms.

Before March 2024

In the old setup, GA4 used the word "conversion" for everything. If you marked an event as important in GA4, it was called a conversion. If that same data flowed into Google Ads, it was also called a conversion. Same word, two different contexts, endless confusion.

After March 2024

Google split the terminology:

  • Key events = important actions tracked in GA4 (what used to be called conversions in GA4)
  • Conversions = key events that have been imported into Google Ads for campaign optimisation

The distinction matters because GA4 and Google Ads count things differently. GA4 key events use last-click attribution by default, whilst Google Ads conversions can use data-driven attribution or other models. The same user action might appear as one key event in GA4 but be counted differently as a conversion in Google Ads.

A practical example

Imagine someone clicks your Google Ad, browses your site, leaves, then comes back via an organic search and buys something.

  • GA4 key event: Credits the purchase to organic search (last click)
  • Google Ads conversion: May credit some value to the ad click (data-driven attribution)

Same purchase. Different attribution. That's exactly why Google separated the terms — to stop people from wondering why their "conversion" numbers didn't match between platforms.

Types of key events you should track

Not every event deserves to be a key event. If you mark everything as important, nothing is important. Here are the key events that most businesses should be tracking:

For e-commerce sites

  • purchase — completed transactions (GA4 tracks this automatically with e-commerce setup)
  • add_to_cart — products added to the shopping basket
  • begin_checkout — users who start the checkout process
  • sign_up — new account registrations

For lead generation sites

  • generate_lead — form submissions, quote requests, demo bookings
  • file_download — downloads of whitepapers, case studies, or resources
  • phone_call_click — clicks on phone number links
  • email_click — clicks on email address links

For content and SaaS sites

  • sign_up — free trial or account registrations
  • subscription_purchase — paid plan conversions
  • video_complete — users who watch a full video
  • scroll_depth — users who scroll past a meaningful threshold (e.g., 90%)

The golden rule

Ask yourself: "If this action happened 100 times today, would I care?" If the answer is yes, it's probably worth marking as a key event. If you'd shrug, leave it as a regular event.

How to set up key events in GA4

Setting up key events is straightforward, but there are two distinct paths depending on whether GA4 already knows about the event.

Method 1: mark an existing event as a key event

GA4 automatically collects certain events (like page_view, scroll, click, and first_visit). If the event already exists, you can mark it as a key event directly in the GA4 interface.

  1. Open your GA4 property
  2. Navigate to Admin → Data display → Events
  3. Find the event you want to promote
  4. Toggle the "Mark as key event" switch to on

That's it. GA4 will start counting that event as a key event going forward. Note that this isn't retroactive — it only applies to data collected after you flip the toggle.

Method 2: create a new event, then mark it

If the action you want to track doesn't exist as an event yet, you'll need to create it first. There are three ways to do this:

Option A: Create in GA4 Interface

  1. Go to Admin → Data display → Events
  2. Click Create event
  3. Define your conditions (e.g., event name equals page_view AND page_location contains /thank-you)
  4. Name your new event (e.g., form_submission)
  5. Save, then mark it as a key event

This method is great for simple events based on page views or existing event parameters.

Option B: Use Google Tag Manager

For more complex tracking — like button clicks, form submissions, or scroll depth — Google Tag Manager gives you far more flexibility.

  1. Create a new tag in GTM with the GA4 Event tag type
  2. Configure your trigger (e.g., form submission, button click)
  3. Set the event name (e.g., contact_form_submit)
  4. Publish the container
  5. Once the event appears in GA4, mark it as a key event

Option C: Use the gtag.js Code Directly

If you're comfortable with code, you can fire events directly:

gtag('event', 'generate_lead', {
  event_category: 'form',
  event_label: 'contact_page',
  value: 50
});

Then mark generate_lead as a key event in the GA4 admin panel.

Important: count method matters

When you mark an event as a key event, GA4 lets you choose how to count it:

  • Once per session — counts only the first occurrence per session (ideal for form submissions and sign-ups)
  • Every event occurrence — counts every time it happens (ideal for purchases, where a user might buy multiple items)

Key Takeaway: Always set form submissions and sign-ups to "Once per session." Set purchases to "Every event occurrence." The wrong setting will silently corrupt your conversion numbers.

Choose wisely. Counting every form_submission event will inflate your numbers if users submit the same form multiple times in a session.

Viewing key event data in GA4 reports

Once your key events are set up, you'll want to actually use the data. Here's where to find it.

The reports snapshot

Your GA4 home screen shows a summary of key events. This gives you a quick pulse check on how your most important actions are trending.

Traffic Acquisition report

Navigate to Reports → Acquisition → Traffic acquisition. This report shows you which channels are driving key events. You can see at a glance whether organic search, paid ads, social media, or direct traffic is generating the most valuable actions.

The key events report

Go to Reports → Engagement → Key events for a dedicated breakdown. Here you can:

  • See total key event counts over time
  • Compare different key events against each other
  • Filter by specific event names
  • Break down by dimensions like source, medium, or campaign

Using explorations for deeper analysis

For more advanced analysis, GA4 Explorations let you build custom reports. You might create a funnel exploration to see how users move from landing page → product page → add to cart → purchase, identifying where they drop off.

Or just ask in plain English

If navigating GA4's interface feels like a maze, tools like Meaning let you skip the clicking entirely. Instead of hunting through menus, you can ask questions like "Which channels drove the most sign-ups last month?" or "What's my purchase conversion rate from organic traffic?" and get instant answers from your GA4 data.

Common mistakes when setting up key events

Even experienced analysts make these errors. Save yourself the headache.

Mistake 1: marking too many events as key events

GA4 allows up to 30 key events per property. But just because you can doesn't mean you should. Stick to 5-10 truly important actions. Too many key events create noise and make it harder to focus on what matters.

Mistake 2: not setting up event parameters

A key event without context isn't very useful. If you're tracking generate_lead, include parameters like form_name, page_location, and value. These parameters let you segment and analyse your key events in far more detail.

If you run Google Ads, remember that key events in GA4 don't automatically become conversions in Google Ads. You need to:

  1. Link your GA4 property to Google Ads
  2. Go to Google Ads → Goals → Conversions
  3. Import the specific key events you want to use for campaign optimisation

Mistake 4: ignoring the attribution difference

As we covered earlier, GA4 and Google Ads attribute key events differently. Don't panic when the numbers don't match — they're not supposed to. Use GA4 key events for website analysis and Google Ads conversions for campaign optimisation.

Mistake 5: not testing before deploying

Always verify your key events are firing correctly. Use GA4's DebugView (Admin → Data display → DebugView) or the Google Tag Assistant Chrome extension to confirm events are being recorded with the right parameters before you start making decisions based on the data.

Key event reporting: metrics that matter

Once you're tracking key events, here are the metrics you should pay attention to:

Key event rate

Key Event Rate is the percentage of sessions (or users) that result in a key event. It is the primary measure of how effectively your site turns visitors into leads or customers. It's calculated as:

Key Event Rate = (Sessions with key event ÷ Total sessions) × 100

For example, if you had 10,000 sessions and 350 resulted in a form submission, your key event rate for form submissions is 3.5%.

Industry benchmarks vary wildly, but as a rough guide:

  • E-commerce purchase rate: 1-4%
  • Lead generation form rate: 2-5%
  • SaaS sign-up rate: 3-7%

Key event value

If you assign monetary values to your key events (and you should), you can calculate the total value generated by each channel, campaign, or landing page. This is incredibly powerful for understanding ROI.

For e-commerce, GA4 pulls this from the value parameter automatically. For lead generation, you can assign estimated values — for example, if 10% of leads become customers worth £1,000 each, each generate_lead event is worth roughly £100.

Key events by channel

Break down your key events by acquisition channel to understand where your most valuable traffic comes from. You might discover that organic search drives the most traffic but paid social drives the highest-value key events. This insight directly informs budget allocation.

If you use a tool like Meaning, you can quickly ask "Which acquisition channel has the highest key event rate?" without building custom reports — it pulls the answer straight from your GA4 data.

Migrating from the old conversion setup

If you had conversions set up in GA4 before March 2024, here's what you need to know:

  • Your data is safe. Nothing was lost in the rename. All historical conversion data now appears under "key events."
  • No action required for GA4. Your existing conversions were automatically renamed to key events.
  • Google Ads may need attention. If you had GA4 conversions imported into Google Ads, check that the link is still active and the events are still being counted correctly.
  • Update your internal documentation. If you have SOPs, dashboards, or reports that reference "conversions in GA4," update the language to "key events" to avoid confusion with your team.

Advanced: using key events with audiences

One of the most powerful (and underused) features in GA4 is building audiences based on key events. For example:

  • Retargeting audience: Users who added to cart but didn't purchase in the last 7 days
  • High-value audience: Users who completed a purchase with a value above £200
  • Engaged prospects: Users who submitted a lead form but haven't returned in 30 days

These audiences can be pushed to Google Ads for targeted remarketing campaigns, making your advertising spend significantly more efficient.

To create a key event-based audience:

  1. Go to Admin → Data display → Audiences
  2. Click New audience
  3. Choose Create a custom audience
  4. Add conditions based on your key events
  5. Set the membership duration
  6. Save and optionally enable Google Ads sharing

Frequently asked questions

What is the difference between events and key events in GA4?

Events are any tracked user interaction in GA4 — page views, scrolls, clicks, and custom actions. Key events are a subset of events that you've flagged as particularly important to your business goals, such as purchases or form submissions.

Why did Google rename conversions to key events?

Google renamed conversions to key events in March 2024 to eliminate confusion between GA4 and Google Ads. The term "conversion" now exclusively refers to key events imported into Google Ads for campaign optimisation, whilst "key event" describes important actions within GA4 itself.

How many key events can I set up in GA4?

GA4 allows up to 30 key events per property. However, best practice is to keep the number between 5 and 10 to maintain focus on the actions that truly matter to your business.

Do key events track retroactively in GA4?

No. When you mark an event as a key event, GA4 only counts it from that point forward. Historical occurrences of the event won't be reclassified as key events, so set up your tracking as early as possible.

How do I check if my key events are firing correctly?

Use GA4's DebugView feature (Admin → Data display → DebugView) whilst browsing your site with debug mode enabled. You can also use the Google Tag Assistant Chrome extension to verify events are being sent with the correct parameters.

Can I assign monetary values to key events?

Yes. You can pass a value parameter with any event, and GA4 will use this to calculate total key event value. For e-commerce, this is typically the transaction amount. For lead generation, you can assign estimated values based on your average customer lifetime value and lead-to-customer conversion rate.

Wrapping up

The rename from conversions to key events might feel like unnecessary jargon, but it actually makes the analytics ecosystem clearer once you understand the reasoning. Key events are your north star in GA4 — the actions that tell you whether your website is achieving its goals.

Set them up thoughtfully, keep the list focused, add meaningful parameters, and review the data regularly. And if you'd rather skip the interface entirely, Meaning connects directly to your GA4 property and lets you ask questions about your key events — and everything else — in plain English. No menus, no filters, just answers.

The most important thing isn't what Google calls them. It's that you're tracking the actions that matter to your business — and actually using that data to make better decisions.