Lastly, I want to spend a few moments discussing a topic that’s most importance to this company and to me personally. Since joining Pinterest, I’ve talked extensively about Pinterest as a positive place online and how maintaining this positivity is a pivotal component of our ethos as a company. It’s also a meaningful differentiator for our platform and a core part of our strategy for growing users and advertisers. Users, especially Gen Z, often crave respite from social media and see Pinterest as a positive alternative. Advertisers for their part, want to be present in a positive, brand-safe environment that can also deliver performance. I recently had the opportunity to speak alongside key thought leaders at the inaugural Youth Online Safety Summit hosted by Commonsense Media, a leading advocacy organization working to ensure that the Internet is healthy, safe and empowering for young people.
It was an honor to be able to speak alongside the surgeon general, Vivek Murthy, about how Pinterest is working to build an alternative social media business model, one that is focused on positivity. We’re not perfect, and we don’t have all the answers. Like the rest of the industry, we have a long way to go, but it is my intention to make Pinterest a safe place for everyone, especially on people. We’re one of the few places online that is about focusing on your own life versus just observing the lives of others, about making plans for what you intend to do. We’ve taken a radically different stance than our competitors, and we’re seeing it pay off in the emotional well-being of our users and in our business outcomes. These principles are at the heart of our technology, our AI and our policies, and we are being accountable and transparent about how we’re doing and sharing our learnings across the industry.
Our company mission is to bring everyone the inspiration to create a life they love and our work to make Pinterest a positive corner of the internet is an integral part of how we embody our mission every day. Now I’ll turn the call over to Julia to share more about our financial performance.
Julia Donnelly: Thanks, Bill, and good afternoon, everyone. Today, I’ll be discussing our full year and fourth quarter 2023 financial results and provide an update on our preliminary first quarter 2024 outlook. All financial metrics, except for revenue will be discussed in non-GAAP terms unless otherwise specified, and all comparisons will be discussed on a year-over-year basis unless otherwise noted. Before I dive into the details of the quarter, I want to echo Bill’s sentiments about the progress we made in 2023 and how far we’ve come in a short period of time. Last year, we generated $3.1 billion in revenue, growing 9% with revenue reaccelerating to double-digit growth in the back half of the year. We’ve been strategic with our investments that enabled us to invest in high ROI projects such as AI for content recommendation and ads and accelerating the pace of innovation across the board.
We did this while driving efficiencies with our infrastructure spend and keeping our total non-GAAP expenses in 2023, roughly flat compared to 2022. This allowed us to deliver $683 million of adjusted EBITDA or a 22% adjusted EBITDA margin, representing 660 basis points of year-over-year margin expansion well above our initial goal at the start of 2023 of 200 basis points. Finally, at our recent Investor Day in September, we shared our long-term outlook with a revenue CAGR in the mid to high teens and EBITDA margins expanding to the low 30s percent range in the next 3 to 5 years. Our recent results and our focus on executing against our strategic priorities sets us up well to achieve these targets over this time frame. Now I’ll discuss our fourth quarter results.
We ended the year with 498 million global monthly active users, representing 11% growth. This is the strongest growth we’ve seen since Q1 2021, with MAU growth accelerating versus last quarter and growing sequentially in all of our geographic regions. We believe that our continued investments to help users find their next use case and quickly pivot from inspiration to action and shopping are paying off as we’ve been able to drive deeper engagement with our users. In the U.S. and Canada, we had 97 million MAUs, growing 2%, up from 1% growth last quarter and adding 1 million MAUs sequentially for the second quarter in a row. In Europe, we had 135 million MAUs, growing 8%, an acceleration from last quarter. In our rest of world markets, we had 266 million MAUs growing 15%, continuing the trend of acceleration throughout 2023.
In Q4, our global revenue was $981 million, up 12% or 11% on a constant currency basis. Our fastest-growing objective was our lowest funnel conversion objective buoyed by strength in the retail vertical, including our shopping ad format. This is a testament to the innovative work we are doing to drive more clicks and conversions for performance advertisers and demonstrates that our business is evolving as we are deploying more lower funnel products and getting access to more performance budgets. Our awareness objective was also relatively resilient, with strength from new formats like Premier Spotlight, as this was the first holiday season with this offering. However, this growth was partially offset by headwinds from the food and beverage category, as these advertisers pulled back spending towards the end of the quarter due to challenges from macro headwinds.
We estimate that the underperformance in the food and beverage category created roughly 1 percentage point of headwind to total revenue growth in Q4. Turning to our geographical breakouts. In the US and Canada, we generated $778 million in revenue, growing 8%. Strength came from retailers and from emerging categories, including financial services. In Europe, revenue was $162 million, growing 32% on a reported basis or 25% on a constant currency basis. Strength in Europe came from retail and CPG categories. Revenue from Rest of World was $41 million, growing 27% on a reported basis or 25% on a constant currency basis. In Q4, ad impressions, which is composed of ad load and total impressions, including both organic and paid impressions, accelerated to 33% growth driven both by increases in total impressions and increases in ad load.
This marks the sixth quarter in a row where we’ve been able to grow both total impressions and ad load demonstrating that ads can grow in tandem with engagement, especially when those ads are relevant to users. During the holiday season, our continued investments in whole page optimization to dynamically flex up ad load when users express commercial intent enabled us to open up more ad supply, especially when users were leaned in to shop during the holiday season. Offsetting the growth in ad impressions was a 16% decline in ad pricing due to our continued work to drive greater platform efficiency for lower funnel advertisers, which lowered prices and improved return on ad spend for those advertisers. Now, I’d like to turn to expenses. While our Q4 revenue grew double digits, our operating expenses declined double digits as we continue to control our expenses diligently and balance investments for future growth.
Cost of revenue in Q4 was $174 million, down 2% due to continued cost optimization work on the infrastructure side, even while MAUs reached an all-time high and engagement continued to grow. Our non-GAAP operating expense was $446 million, down 12%. Our heightened focus on driving operational efficiencies throughout the business showed through again this quarter. All of our operating expense line items declined year-over-year, led by sales and marketing, which declined 18% as we lapped our large brand marketing campaign from Q4 2022. These efforts led to another strong quarter of adjusted EBITDA coming in at $365 million, an all-time high. Q4 adjusted EBITDA margin was 37%, up 1,400 basis points year-over-year. Finally, we ended the year with cash, cash equivalents and marketable securities of $2.5 billion.
Now, I’ll discuss our preliminary guidance for the first quarter. We expect Q1 2024 revenue to be in the range of $690 million to $705 million, representing 15% to 17% growth and a meaningful acceleration from our Q4 ’23 revenue growth. It’s also worth noting that our guide implies up to a 500 basis point acceleration on top of a stable comp from last year, since revenue growth from Q4 ’22 to Q1 ’23 was relatively consistent. I’d like to provide some additional color and context behind this guide for Q1. First, we’re in the midst of an adoption curve of our lower funnel advertising products. In 2023, many of our largest and most sophisticated advertisers took advantage of lower funnel ad products like mobile deep linking, shopping ads or API for conversions.
These advertisers have seen sustained performance gains with these formats and are growing their budgets with us, the benefits of which we’ve seen throughout the course of the year and accelerating into Q1, which is off to a strong start, as Bill mentioned. We see multiple of our large sophisticated retail advertisers allocating more of their performance budgets to us after seeing a longer track record of return on ad spend. As a result, we are beginning to garner more meaningful shares of their overall ad budgets, and we see more of this adoption curve yet to play out with many of our retailers. Second, we launched direct links in late Q3 and early Q4 to help drive more clicks and conversions for all of the other advertisers who may not have as much mobile app penetration and were not good candidates for mobile deep linking.
We created value for those advertisers by doubling the clicks we drove for advertisers in Q4. However, we believe the value capture from direct links will come over the course of 2024 and beyond as those advertisers use their own analytics to measure attribution from Pinterest and incrementally increase their budgets with us as a result. Third, our Q1 revenue guidance includes an emerging contribution from third-party ad demand. We are pleased with how this is tracking and we’ll continue to learn, iterate, optimize and ramp over the course of this year and beyond. Finally, our guidance takes into account a modest impact from foreign exchange rates. Turning to our Q1 expense guidance. We expect non-GAAP operating expenses of $450 million to $465 million, growing 9% to 13%.
