term user value as notifications improve. As a result, we expect platform WAU will continue to fluctuate in the near term, which is an intentional trade-off as we focus on relevance, retention, and overall improved user experience. Now let us turn to revenue. Q4 revenue was $69,000,000, up 7% year over year. This was our highest ever quarterly revenue, reflecting continued strong self-serve advertiser demand, improved sales productivity, and better yields driven by product improvements. We saw year over year growth in both customer count and average customer spend, while ARPU increased 13% year over year, all without an increase in ad load. Advertisers benefited from higher click-through rates while we grew our active customer base and associated net new advertiser spend. In short, our ad stack investments are delivering measurable improvements. We are seeing positive effects in our self-serve platform, including incremental advertiser spend, improving advertiser mix and retention, and better operating efficiency from a more streamlined sales model. As we continue to roll out new ad formats and apply AI to optimization and creative workflows, our focus remains on steadily improving monetization and advertiser outcomes over time. Our self-serve platform lets businesses of any size quickly create and run their own ads on Nextdoor. By removing friction for advertisers, we have created an efficient path for businesses to leverage our neighborhood data and AI to reach verified household decision makers and measure results clearly. Our self-serve channel was again a core growth driver, and remains a key component of our monetization strategy. Q4 self-serve revenue grew 32% year over year, and comprised roughly 60% of total revenue. Now let us move to profitability. Q4 GAAP net loss was $4,000,000, or negative 6% margin, representing 13 points of year over year improvement. Q4 adjusted EBITDA was $8,000,000, an 11% margin, representing six points of year over year improvement driven by revenue scale and continued broad-based operating expense leverage. Like revenue, Q4 was the strongest adjusted EBITDA quarter in our history. Our strong Q4 results allowed us to achieve positive adjusted for the full year 2025, twelve months ahead of schedule, reflecting our continued focus on efficiency and productivity. Revenue per employee increased which is another good proof point 26% year over year in Q4. of our revenue growth and the operating leverage we drove through 2025. At quarter end, we had $405,000,000 in cash, cash equivalents, and marketable securities, and zero debt. In Q4, we repurchased 2,500,000 shares at an average price of $1.77. Looking ahead, we continue to prioritize operational investments that we feel will drive long-term value for the platform. Now let us turn to our financial outlook. We expect Q1 revenue of $57,000,000 to $59,000,000, representing 7% year over year growth at the midpoint of the range, and adjusted EBITDA of negative $6,000,000 to negative $4,000,000, representing negative 9% adjusted EBITDA margin at the midpoint. Here are some factors to consider related to our Q1 outlook.