Solved: Multiple Pixels on One Website - Impact on Ads?

Hi there,

Saw your question about using one vs two pixels and thought I'd give you some of my thoughts on it. I’ve seen this come up a few times with clients and it’s a good question to ask, specialy when you’re planning to scale things up. Getting this foundation right from the start will save you a world of headaches later on.

Happy to give you some initial guidance based on my experience running paid ad campaigns.

I'd say you should stick to one pixel...

Right, let's get straight to it. My honest advice would be to stick to one single pixel per website. Always. While it's technically possible to install two pixels from two different ad accounts onto one website, it’s a recipe for disaster in 99% of cases. The short answer is yes, it will almost certainly create problems for your ads.

The main issue is data clarity and attribution. When you have two pixels firing on the same events (like a page view, an add to cart, or a purchase), you're essentially splitting your data. Meta's algorithm relies on clean, consistent data to learn who your customers are and find more people like them. When you feed it conflicting or duplicate signals from two different sources for the same user action, it gets confused. Which pixel gets credit for the conversion? How does the algorithm optimise delivery when it's getting mixed messages? It's like trying to have two different managers telling one employee to do the same task in two slightly different ways. The result is usually confusion and poor performance.

I remember working with an eCommerce brand that had been working with another freelancer who, for reasons we never quite figured out, had set them up with two pixels on their Shopify store. One was for their main ad account, and another was for a 'testing' ad account. The reporting was an absolute nightmare. The purchase numbers in Ads Manager never matched what was in their store's backend. We couldn't tell which campaigns or ads were genuinely driving results because both pixels were claiming conversions. It made it impossible to make informed decisions. We couldn't reliably build retargeting audiences because the data was fragmented. Before we could even think about scaling, our first job was to do a massive clean-up, strip everything back to one pixel, and rebuild the data foundation from scratch. It set them back weeks, if not months.

We'll need to look at how this affects scaling...

You mentioned you're planning to scale, and this is where a single-pixel setup becomes absolutly non-negotiable. Scaling on Meta isn't just about increasing your budget. It's about feeding the algorithm enough high-quality, consistent data so that it can efficiently find new customers at a profitable cost. A single, 'mature' pixel that has tracked thousands of events is your most powerful asset.

When you have one pixel, every single conversion, every 'add to cart', every 'initiate checkout' strengthens it. This makes your custom audiences more accurate and your lookalike audiences more potent. A lookalike audience built from a pixel with 10,000 purchase events is going to be far more effective than one built from a pixel that only has 5,000 because its data was split with another pixel.

This is something we see all the time with B2B SaaS clients trying to scale. They often plateau because their acquisition costs get too high. One of the first things we analyse is their data setup. A clean funnel and reliable tracking are fundemental. If the data is messy, you can't properly split test creative, you can't trust your audience performance, and you can't increase customer lifetime value because you don't have a clear picture of the customer journey. Trying to scale with two pixels is like trying to build a skyscraper on foundations made of sand. It'll collapse as soon as you try to add more weight (i.e., ad spend).

A solid campaign structure is built on this data. You want to be able to structure campaigns by funnel stage. For instance, a Top-of-Funnel (ToFu) campaign using broad or interest-based targeting, a Middle-of-Funnel (MoFu) for retargeting website visitors, and a Bottom-of-Funnel (BoFu) for retargeting people who've added to cart. This structure relies entirely on the pixel correctly identifying and segmenting users based on their actions. With two pixels, a user who visited a product page might be in one pixel's audience, but when they add to cart, that event might be captured by the second pixel. The user then falls out of your retargeting sequence. Its just broken.

You'll need a clear strategy for using multiple ad accounts...

Now, you also mentioned using two ad accounts. This is different from using two pixels. There are sometimes valid reasons to have multiple ad accounts for a single business. For example, if you have distinct brands or business units, or if you're working with an agency who needs to use their own ad account. However, even in these scenarios, the best practice is for all ad accounts to use the same single pixel.

You can (and should) achieve this using Facebook Business Manager. You 'own' the pixel in your Business Manager, and you then grant access or 'share' that pixel with the other ad accounts. This way, all advertising activity, regardless of which ad account it comes from, feeds data back to that central, unified pixel. Everyone benefits from the collective learning, and you maintain a single source of truth for your website's data.

If you set up two ad accounts each with their own pixel, you are actively working against yourself. You're creating two separate, weaker data silos instead of one strong, unified data hub. When you want to retarget website visitors, you'd have to create the audience in both ad accounts, and each would only have a partial list of those visitors. It's inefficient and will deliver poor results.

You probably should focus on a solid foundation...

So, instead of thinking about adding a second pixel, I would double down on getting the structure right with one. Your path to scaling looks like this: one website, managed by one Business Manager, which owns one Pixel. That pixel is installed correctly across your entire site, tracking all the standard and custom events that matter to your business.

From there, you build your campaigns within a single ad account (or multiple accounts sharing that one pixel). You start by testing audiences methodically. For a new account, you'd begin with detailed targeting (interests, behaviours). As soon as you have enough data (we usually say at least 100 conversions, but more is much better), you build your retargeting audiences (MoFu/BoFu) and then start testing lookalike audiences based on your highest-value events, like purchases.

I remember working with a women's apparel brand, where we focused on a super clean, single-pixel setup, which allowed us to build a robust funnel structure. We created potent lookalikes from their past customer lists and ran highly effective dynamic product ads to their BoFu audiences. Because of this, we achieved a 691% return on ad spend as the algorithm had a crystal-clear picture of who to target at every stage. We would never of been able to achieve that with a messy, two-pixel setup.

This is the main advice I have for you:

This is a lot to take in, I know. Getting these foundational elements right is honestly one of the most challenging parts of paid advertising, and it’s where we see so many businesses struggle. They focus on the ads themselves without realising the underlying data structure isn't sound, and then they wonder why they can't scale profitably.

It's about understanding your audience, optimising your targeting, creating compelling ads, and fine-tuning your landing page - all of which relies on good data. That's where getting professional advice can make a huge difference. With years of experience and a deep understanding of the advertising landscape, we can help you identify the best strategies, build that solid foundation, and ensure that every pound you spend is working as hard as it possibly can to grow your brand.

If you'd like to chat through your specific situation in more detail, we offer a free initial consultation where we can review your strategy and account together. It's a great way to get a taste of the expertise we can bring to your project. Just get in touch if that sounds helpful.

Regards,
Team @ Lukas Holschuh