generate_lead or form_submit as the GA4 key event?
Mark generate_lead, and send it from your own trigger on the form's success step. form_submit from enhanced measurement fires on any form on the page, newsletter and search boxes included. On 9 Nov 2026 we read the public tags of the study sites that list it: of 101 sites with form_submit as a key event, 74 have no GTM tag for it and 71 of those have enhanced measurement form interactions on, so the key event fires on any form.
Check this on your own site
Free. Public tags only. Your result opens on the scan page.
What is the difference between the two events?
form_submit | generate_lead | |
|---|---|---|
| Who sends it | GA4 itself, if enhanced measurement form interactions is on (Analytics Help) | You, with a tag or code. Google lists it as a recommended event |
| When it fires | When a visitor submits a form on the page | When your trigger says a lead was captured |
| Which forms | Any form: contact, newsletter, search, login | The ones you wire up |
| A failed or empty submit | Can count | Not counted, if the trigger waits for the success step |
A key event is any event you mark as important in GA4 (key events vs Google Ads conversions). The mark does not check what the event means.
What do sites mark as the key event?
On 9 Nov 2026 we re-read the public Google tag and GTM containers of every study site whose Google tag lists form_submit or generate_lead as a key event. No browser, no forms.
form_submit | generate_lead | |
|---|---|---|
| Sites with it as a key event | 101 | 102 |
| A GTM tag sends it | 27 | 64 |
| No GTM tag sends it | 74 | 38 |
| No GTM tag, enhanced measurement form interactions on | 71 | 24 |
The last row is the one to read. For 71 of 101 form_submit sites, nothing in the container sends the event, and the Google tag has form interactions switched on. Their key event fires on any form submit. 15 sites mark both events, and on none of the 15 do the two tags share a trigger.
Which trigger sits behind each event?
For the sites where a GTM tag does send the event, we sorted the trigger on that tag. A site can have more than one tag.
| Trigger on the tag | form_submit sites | generate_lead sites |
|---|---|---|
| Custom dataLayer event | 20 | 54 |
| Form submission trigger | 4 | 7 |
| Page load, DOM ready or history change | 4 | 11 |
| Click | 0 | 2 |
| No event condition | 1 | 0 |
generate_lead mostly comes from a custom event (54 of 64 sites), which means someone pushed it from the page code or the form tool. A page-load trigger sounds like "every page", so we checked it. 18 sites send one of the two events on a page-load trigger or with no event condition. All 18 also carry another condition on the same trigger (a page, URL or variable test). We did not read what the condition matches, so we do not call any of them an every-page event. For the Google Ads side of that question, see page-view conversions with a URL rule.
Which one should be the key event?
- One real lead form: send
generate_leadwhen the form's success message or thank-you step shows, and mark that one. Google's own advice leans the same way. - Several forms: one key event per form type is fine, but name them apart (
generate_leadwith a form name parameter, or your own event name). A singleform_submitkey event cannot tell a demo request from a newsletter signup. - You keep
form_submit: turn off form interactions in enhanced measurement, or add a condition so it only counts your lead form. Otherwise the key event fires on forms that are not leads. - Both are key events and both go to Ads: one lead can count twice. See duplicate conversions in GTM.
How do I check my own property?
- In GA4, Admin, Events. See which of the two is marked as a key event.
- In Admin, Data streams, your web stream, Enhanced measurement, check whether Form interactions is on.
- Open your site with DebugView or the GTM preview. Submit the newsletter box, then the lead form. If
form_submitshows for both, it cannot be your lead key event. - In GTM, search the container for a GA4 event tag named
generate_leadand open its trigger. A form success event or a custom event is what you want. A bare page view is not.
What can't we see from outside?
- Whether a key event is imported into Google Ads, and whether the Ads action is primary or secondary. GA4 imports can't be seen from outside.
- Events sent by code outside GTM or from a server container. A site with "no GTM tag" may still send
generate_leadfrom its own code. - Whether enhanced measurement form interactions fires on a given form. We see that the setting is on, not which forms it catches.
- The condition behind the 18 page-load triggers.
Check what your Google Ads and GA4 setup really counts with the free scan.
FAQ
Should I mark form_submit or generate_lead as the GA4 key event?
generate_lead, sent from your own trigger when the form succeeds. form_submit from enhanced measurement can fire on any form on the page.
Why does my form_submit count look too high?
If form interactions are on in enhanced measurement, GA4 sends form_submit for every form submit, including newsletter and search boxes. Turn it off or add a condition.
Can I mark both as key events?
You can, but one lead may then count twice if both reach Google Ads. Pick one for the lead.
Run the free scan on your site.
Fireshift reads what your site tells Google Ads, GA4 and Meta from the outside. No install, takes seconds.