The best way to track HubSpot Forms submissions as conversions in Google Ads

Google Ads can bring a steady stream of new leads and customers into a business, but wiring up conversion tracking properly is more fiddly than it should be.

If you try to use Google Tag Manager, you'll end up writing custom code to catch form submissions, then juggling triggers, tags, variables, and a long list of other settings.

The simpler options aren't much better. Counting visits to a thank you page quietly drops as much as 30% of your conversions, because of ad blockers, privacy features in browsers like Safari, or a prospect who clicks your ad on their phone and only submits your form hours later from a laptop.

So what actually works?

This article walks through a better way to track conversions in Google Ads when someone fills out a form built with HubSpot Forms, using an approach called server-side tracking.

The common ways of tracking conversions in Google Ads, whether that's counting thank you page views or firing events through Google Tag Manager, all share the same blind spots. Research suggests these methods can miss up to 30% of conversions.

A handful of things cause this:

• Ad Blockers. They stop the Google Tag from ever firing in the visitor's browser, so nothing the visitor does on your site gets recorded.
• Browser privacy features. Browsers like Safari actively cut off the Google Tag from following visitors past a day or so, so a click today and a submission three days later never get connected.
• People switching devices. A prospect might click your ad on their phone but come back and fill out your form later from their laptop, and browser tracking has no way to link those two moments together because they happen on different devices.

This is exactly why server-side tracking matters. Instead of waiting on something to happen in the browser (like a visitor landing on a thank you page) and hoping the Google Tag catches it, you send a direct, private message to Google with the lead's details, so ad blockers and privacy settings can't get in the way.

The numbers back this up. Google's own data shows server-side tracking tends to deliver a 23% average increase in total recorded conversions and a 10% cut in cost per conversion, largely because Google's algorithms have better data to learn from and can put your ads in front of the right people.

There are two main ways to approach this, and which one fits depends on when you want the conversion to show up in Google Ads.

A tool like Converly makes it simple to fire a server-side conversion to Google Ads the moment someone submits your HubSpot form.

Rather than wrestling with Google Tag Manager to detect the submission, pull out the lead's details, hash them with SHA-256 and hand them off to Google's API, you get a clean visual builder for putting your conversion flow together.

You pick a trigger (like a new submission on your HubSpot form) and choose the actions that should follow it (like recording a conversion in Google Ads).

From there, Converly handles it all for you. It watches for new submissions, takes the respondent's name, email and phone number, hashes them with SHA-256, and passes them to Google Ads. It also picks up the GCLID and other signals about how the person found you, and sends those along with the conversion. That gives Google a much better shot at tying the conversion back to the exact campaign, ad and keyword that they originally clicked.

The result is every benefit of server-side tracking (that 23% average lift in recorded conversions and 10% drop in cost per conversion) with no custom code, no need to understand SHA-256, and no wrangling Google's API yourself.

If your HubSpot form submissions feed into your CRM (which, since HubSpot Forms and the HubSpot CRM live in the same platform, they do automatically), you can hold off and send the conversion back to Google Ads later in the sales cycle instead, once a lead actually turns into a paying customer.

The way to do it is to capture a bit of extra data with every submission and store it on the contact record. Here's how that works:

Here are the four big reasons it's the most dependable way to track conversions:

Old-school tracking (like counting thank you page visits, or using Google Tag Manager) depends on scripts loading in the visitor's browser, and ad blockers and privacy-first browsers frequently stop those scripts from loading at all.

Recent research puts the share of internet users running some form of ad blocker at north of 30%.

But because server-side tracking sends the conversion straight to Google's servers, the whole thing stays invisible to ad blockers, and every lead gets counted.

Apple's Intelligent Tracking Prevention (ITP) tends to clear tracking cookies within a day or two, so the link between an ad click and the eventual conversion vanishes whenever someone doesn't submit the same day.

Server-side tracking sidesteps that by sending the name, email, phone and so on to Google with each lead, which lets Google tie the conversion back to the original ad click no matter how long the gap between click and submission.

Plenty of leads will first come across your site on one device (their phone, say) and then hold off until they're at a computer to actually fill out your form.

Ordinary browser tracking can't join those two visits because they happen on separate devices. But by sending identity data (like the lead's name, email, and so on) straight to Google's servers, it lets Google stitch the sessions together and give your ads proper credit for starting things off.

On top of everything else, browser-based tracking invites other mistakes (particularly if you do things like track thank-you page visits, or clicks of the form's submit button). A user could enter the wrong email address or miss a required field, but because they clicked the submit button the conversion gets counted. And then when they fix the error and submit the form again, you have counted 2 conversions for one lead.

Server-side tracking is far tidier. It logs a conversion only when a submission genuinely goes through, not when a thank you page happens to load or a button is clicked, so your Google Ads conversion counts stay much closer to the real number of leads you're generating.

Across 15 years leading marketing teams, I've spent millions of dollars on Google Ads and built more reports than I can count trying to see what was genuinely working.

Here are the 3 I kept coming back to:

Most businesses bid on a spread of keywords across several campaigns, often for different services (a financial advisory firm might bid on retirement planning in one place and estate planning in another).

This report shows which of those keywords are actually producing conversions, rather than just racking up impressions and clicks that never turn into real leads.

It makes clear which keywords are working for your business and which aren't, and ultimately which ones you should put more budget into to drive more leads.

If you're feeding conversions back to Google Ads from your CRM, you can attach the value of each one, pulled from the Deal value on that contact's record.

That matters because customers aren't all worth the same. For a wealth management firm, a client who comes in through a basic financial review campaign is worth a fraction of one who arrives via a high-net-worth planning campaign, so treating them equally would be a mistake.

Send a conversion value to Google Ads from your CRM and you can run reports showing you earned $1000 from leads on one campaign and $10,000 from another. That makes deciding where your budget should go far more straightforward.

This report is great for businesses that win most of their clients locally (financial advisors, accounting firms, law practices, and the like). It breaks your conversions down by geographic region.

You can keep it broad (country, state or city) or drill right down to an individual postcode. Either way, you get to see whether your leads are genuinely coming from the areas you want to serve, or whether budget is leaking into suburbs too far away.

With that information in hand, Location Bid Adjustments let you act on it. You can tell Google to bid harder in the postcodes that pay off best, and ease off (or stop entirely) in the ones that generate impressions and clicks but never turn into leads and customers.

Getting proper conversion tracking set up in Google Ads can genuinely move the needle on your results.

It gives you the numbers you need to make manual tweaks (bidding up on particular keywords or locations), and it feeds Google's algorithms the data they need to handle automated bidding for you.

But all of that hinges on the conversion data being accurate. Track thank-you page visits or fire events from the browser through Google Tag Manager, and you're not really sending solid data, and your Google Ads results will slide because of it.

So whatever setup you land on, and whenever you choose to fire the conversion (at the point of submission, once the lead becomes a customer, and so on), sending it server-side is what gets you the best results.