GA4 vs Google Ads Conversions | Why They Differ

The short answer: GA4 and Google Ads count conversions with different rules: different dates, attribution models, counting methods and conversion sources. A small, steady gap is normal. A large or growing one usually means the same action is counted twice, or click IDs are not reaching the CRM. Checked against Google's help pages on 23 October 2026.

Why the two numbers differ

Different dates. Google Ads attributes a conversion back to the date of the ad that led to it, not the day it happened. Google's help page describes this as the ad impression date. GA4 reports the day the event happened.
Processing delay. Google says to allow 24 to 48 hours for data to sync and process between Google Analytics and Google Ads before you compare, and that conversions can be reported up to 90 days after the click.
Different attribution. Google's help page on conversions and key events says conversions use data-driven attribution, while key events use last non-direct click. The same sale can be credited differently in each.
Different counting. Google Ads can count every conversion or only one per interaction. GA4 key events count either once per event or once per session.
Primary and secondary actions. Primary actions feed the Conversions column and bidding. Secondary actions appear only in All conversions. A page view or add-to-cart marked as primary with a value can inflate totals.
View-through and modelled conversions. View-through conversions are left out of the default Conversions column, and cross-device conversions are modelled.
Invalid traffic. Google removes some conversions later if it detects spam or invalid traffic, so a number can drop slightly after you first read it.
Tracking set-up. Tags that fire twice, or fire with the wrong conversion ID or label, change the totals.

Duplicate conversions: how to find them

If Google Ads shows more conversions than your CRM can explain, look for the same action counted twice:

Two tags for one action. A Tag Manager tag and a hard-coded tag, or a plugin and a tag, both fire on the thank-you page. Check with Tag Manager preview.
Two conversion actions for one event. A native Google Ads conversion and an imported GA4 key event both set as primary. Google says conversions created from GA4 key events default to secondary, to avoid counting the same event twice for bidding. Keep one primary source for each action.
Counting method. A key event counted once per event will count a reload or a second submission; once per session will not. In GA4 you change it under Events, Key events, Change counting method. It applies to future data only. The default depends on how the key event was created, so check rather than assume.
A reloadable thank-you page. Anyone who refreshes it, or reaches it directly, can create another conversion.
Non-purchase actions with values. Google advises against setting page views or add-to-cart as primary with an assigned value.

A related problem across platforms is covered in Meta and Google both claim the same conversion.

Diagnose it in two hops

Do not compare three systems at once. Compare two, then move on.

Hop 1: Google Ads against GA4. Use the same dates, the same time zone and a window that allows for processing. A gap here points to tags, conversion settings, counting or modelling. Fix it before you look further.
Hop 2: GA4 against the CRM. A gap here points to the handoff from form to CRM: forms that do not fire the event, leads that arrive by phone or email, duplicate contacts, or click IDs and UTM tags that never reached the record. See why GA4 and your CRM never match.

If hop 2 is where it breaks, count how many Google Ads leads kept a click ID with the GCLID coverage checker.

Which number to trust

Neither is the final answer. Google Ads numbers are what bidding learns from, so they matter for optimisation. GA4 describes on-site behaviour across all channels. The CRM records qualified leads and closed deals, so it is the reference for business outcomes. Use Google Ads to manage Google campaigns, GA4 to understand behaviour, and the CRM to judge whether either produced customers.

How to close the gap

Remove double-counted conversion actions, and keep one primary source for each action.
Count the action that matches the business goal, such as a qualified lead, not only a form fill.
Capture the Google click ID on every form and save it on the CRM record.
Send qualified leads and closed deals back to Google Ads. See Google Ads offline conversions from your CRM.
Write down your settings (attribution model, counting method, primary actions) and re-check them after any change to tags or consent.

Related: conversion tracking: a practical setup guide, GA4 and Tag Manager setup and a free Google Ads audit. If you run the account in South Africa, see Google Ads management in South Africa.

Questions people ask

Is it normal for GA4 and Google Ads to show different conversions?

Yes. They use different dates, attribution models, counting methods and conversion sources, so small, steady differences are expected. Large or growing gaps are worth investigating.

How do I fix duplicate conversions in GA4 and Google Ads?

Check whether two tags fire for the same action, whether a native conversion and an imported key event are both primary, and whether the counting method suits the action. Keep one primary source for each action and test with Tag Manager preview.

Why does Google Ads show more conversions than GA4?

Common causes are the same action counted from two sources, a different attribution model, a different counting method, conversions credited to the ad date instead of the conversion date, and modelled or view-through conversions.

Why does GA4 show fewer conversions than Google Ads?

GA4 may lose events to consent choices or blockers, or fail to link a visit to Google Ads when click IDs are missing. It also credits conversions to other channels that Google Ads cannot see.

Which conversion number should I optimise on?

Optimise on the action closest to revenue that has enough volume, such as qualified leads sent back from the CRM, and check it against closed deals.

GA4 vs Google Ads conversions: why the numbers differ