Amy Weaver
President and Chief Financial Officer at Salesforce
Great. Thank you, Bret, and congratulations, Brian.
I'm pleased to report strong top and bottom line financial results for Q2. That is pleased to report strong top and bottom line financial results in Q2. As you've heard from Marc and Bret, our diversified portfolio remains well positioned to help our customers both grow and drive efficiencies in their business. Our customers are relying on us more than ever to be their trusted adviser, partnering with them on their digital road map.
Now let me walk through our results for Q2 of fiscal '23, beginning with top line commentary. Total revenue for the second quarter was $7.72 billion, up 22% year-over-year or 26% in constant currency. FX continued to represent a headwind as the dollar continued to strengthen throughout the quarter. In Q2, the headwind from FX was about $50 million more than we had guided.
A few highlights from the quarter. Sales Cloud continues to be a critical piece of our customers' success, helping companies drive more productive growth. In Q2, Sales Cloud grew 15% year-over-year and 19% in constant currency. Service Cloud grew 14% year-over-year and 18% in constant currency as we help our customers realize efficiencies and cost savings.
As customers focus on their digital strategy and transformation, we continue to see growing multi-cloud adoption due to the number of customers who have purchased five or more clouds, again grew in double digits. And Slack continued to outperform our revenue expectations with revenue of $381 million. Slack continues to gain traction with customers. And in Q2, seven of our top 10 deals included Slack. And for the fifth consecutive quarter, the number of customers spending greater than $100,000 with Slack, grew by more than 40% year-over-year.
Now for a quick update on data. I'm pleased to say that data passed $1 billion of revenue this quarter. And with that, all of our five clouds are now generating more than $1 billion in revenue a quarter. Data growth of 12% or 13% in constant currency was driven by MuleSoft total revenue growth of 15% and Tableau growth of 9%. As a reminder, approximately half of MuleSoft and Tableau's total contract value is recognized in period, resulting in more quarterly volatility than our other core products.
Turning to revenue attrition. Rates remain at record lows, ending Q2 at approximately 7.5%. Q2 non-GAAP operating margin was 19.9%, driven by our continued focus on disciplined decision-making and prioritization. Q2 GAAP EPS was $0.07 and non-GAAP EPS was $1.19. Mark-to-market accounting of the company's strategic investments benefited GAAP EPS by $0.03 and non-GAAP EPS by $0.04. Operating cash flow was $334 million in Q2, down 13% year-over-year. Capex was $203 million, resulting in free cash flow of $131 million, down 24% year-over-year.
Now before getting to our RPO performance and guidance, I'd like to address the current economic environment. As both Marc and Bret mentioned, we started to see more measured buying behavior from our customers, which began in the last month of the quarter. This resulted in stretched sales cycles, additional deal approval layers and deal compression.
In addition, we saw slowing in our create and close, Slack self-serve and SMB businesses, which tend to be leading macro indicators. Geographically, this behavior was most pronounced in North America and major European markets, while Japan was relatively more resilient. From an industry perspective, retail, consumer goods and communications and media were the most impacted, while high tech, energy and financial services stayed more consistent during the quarter. And from a product perspective, commerce and marketing saw more pronounced decelerations, while sales and service remains strong.
Turning to remaining performance obligation, or RPO, which represents all future revenue under contract. It ended Q2 at approximately $41.6 billion, up 15% year-over-year. Current remaining performance obligation, or CRPO, was approximately $21.5 billion, up 15% year-over-year and 19% in constant currency. This includes one point of incremental FX headwind beyond our Q2 guidance.
Moving to Q3 guidance. We expect revenue of $7.82 billion to $7.83 billion, or approximately 14% growth year-over-year and 18% in constant currency. This reflects a $250 million FX headwind. We also expect the $380 million contribution from Slack. As a reminder, Q3 represents the fifth quarter of Slack contributions to revenue. Therefore, the year-over-year growth rates will be normalized.
CRPO growth is expected to be approximately 12% year-over-year or 15% in constant currency. And we expect GAAP EPS of $0.09 to $0.10 and non-GAAP EPS of $1.20 to $1.21.
Now turning to our full year fiscal '23 guidance. We are now guiding to fiscal '23 revenue of $30.9 billion to $31.0 billion or approximately 17% growth year-over-year, 20% in constant currency. This incorporates the trends in customer behavior that we saw beginning in July. The total year-over-year FX headwind is now $800 million, an incremental $200 million year-over-year since our previous guidance. As a reminder, the currencies most impacting our revenue are the euro, the British pound, the Japanese yen and, to a lesser extent, the Australian dollar.
Our guidance continues to assume a $1.5 billion contribution from Slack. As a company, we remain committed to profitability over the long term. And while we see a more deliberate customer buying behavior, I am pleased to hold our fiscal '23 non-GAAP operating margin guidance at 20.4%, an increase of 170 basis points year-over-year. This margin guidance includes roughly 100 basis points of headwind from Slack.
As a reminder, because our regional revenue and expenses are generally in the same currencies, there tends to be a natural FX hedge in our operating margin. For the full year, we expect GAAP EPS of $0.38 to $0.40 and non-GAAP EPS of $4.71 to $4.73. And please recall that our OIE and EPS guidance assumes no further mark-to-market adjustments of our strategic investment portfolio.
We are updating our fiscal '23 operating cash flow guidance to approximately 16% to 17% growth year-over-year. Our guidance continues to assume a 3-point headwind from cash taxes associated with tax law changes requiring the capitalization of certain R&D costs. We expect capex to be slightly above 2% of revenue in fiscal '23, a nominal increase over last quarter's guide, reflecting the revised full year revenue guidance. This results in free cash flow growth of approximately 18% to 19% for the fiscal year.
So to close, as our customers and their executive teams, including the CEO, CIO and CFO, focus on their digital investment strategy, we are well positioned with our diversified product portfolio to help drive efficiencies and growth. And we are laser-focused on disciplined decision-making with a commitment to achieving our operating margin guidance. Lastly, let me echo Bret and Marc.
We are very, very pleased to be announcing our new share repurchase program today. This step is a reflection of the confidence that we have in the future of Salesforce. And I look forward to seeing everyone at Investor Day on September 21, where we will go into even more detail on our capital allocation strategy.
Now Emma, let's open up the call for questions.