Ed McGowan
Executive Vice President & Chief Financial Officer at Akamai Technologies
Thank you, Tom. As Tom mentioned, Akamai delivered a strong and very profitable quarter in Q3. In my remarks today, I'll cover our Q3 results and then provide some perspective on Q4, share some details on our recent customer contract acquisitions and close with our increased full year 2023 guidance.
First, let's discuss revenue. Total revenue for the third quarter was $965 million, up 9% year-over-year as reported and in constant currency. In the third quarter, security revenue was $456 million, growing 20% year-over-year as reported, and 19% in constant currency. Security revenue growth was primarily driven by continued strength in our segmentation product, which is now over $100 million on an annualized run rate basis and up 97% year-over-year.
I'll note that during the quarter, we had approximately $6 million of one-time segmentation license revenue. Adjusting for the one-time license revenue, total security growth for the third quarter would have been 18% year-over-year as reported, and 17% in constant currency. And segmentation revenue growth would have been approximately 62% year-over-year and 60% in constant currency.
In addition to strength in segmentation, we also saw very strong growth in our flagship Web Application Firewall or WAF product family. This growth was primarily driven by stronger than expected adoption of new security bundles offered to new and existing customers that we introduced this year. The new security bundles include additional security entitlements, such as more security policies, additional security configurations, and more advanced rate control policies. Many existing customers are seeing greater value in these new bundles, and as a result are spending more with us.
Moving to compute. Revenue was $130 million, growing 19% year-over-year as reported and in constant currency. On a combined basis, our security and compute business product lines represented 61% of total revenue, growing 20% year-over-year and 19% in constant currency.
Shifting to delivery, revenue was $379 million, declining 4% year-over-year as reported and in constant currency. It's worth noting that delivery was aided by approximately $4 million in revenue from the selected CDN customer contracts we acquired from StackPath.
International revenue was $467 million, up 11% year-over-year and up 9% in constant currency. Foreign exchange fluctuations had a negative impact on revenue, a $3 million on a sequential basis and a positive $7 million benefit on a year-over-year basis.
Moving now to company profitability. Non-GAAP net income was $251 million or $1.63 of earnings per diluted share, up 29% year-over-year and up 28% in constant currency. These especially strong EPS results exceeded the high end of our guidance range by $0.11, driven primarily by higher revenues and continued progress on the cost savings initiatives we outlined over the last few quarters. As an example, we continued to reduce our third-party cloud spend by migrating internal workloads to our connected cloud platform. In Q3, our third-party cloud spend declined 26% year-over-year.
Moving to margins. Our cash gross margin was 73%. Included in our Q3 cost of goods sold was approximately $5 million of transition services agreement or TSA costs paid to StackPath. With customer contract acquisitions, TSA payments are used to cover the sellers customer-related network and support costs during the migration period. I will provide further detail on expected TSA costs going forward in the guidance section in a few moments.
Adjusted EBITDA margin was 43%, and our non-GAAP operating margin is 31%, 2 points ahead of our guidance, driven by our revenue outperformance and continued focus on driving down costs across the businesses.
Moving now to cash and our use of capital. As of September 30th, our cash, cash equivalents, and marketable securities totaled approximately $2.1 billion, which includes the proceeds from the convertible debt raise we did during the quarter. As a reminder, in August, we issued $1.265 billion of senior unsecured convertible debt that will mature on February 15th, 2029. The notes will bear interest at a rate of 1.125% per year payable semiannually.
Finally, the net proceeds of approximately $1 billion from this offering have been invested in highly liquid marketable securities. These securities yield approximately 5.25% on a weighted average basis with maturities close to May 2025, as we intend to use these proceeds to pay-off approximately $1.15 billion of convertible notes that mature in May 2025.
For the third quarter, we spent roughly $113 million to repurchase approximately 1.1 million shares. We now have roughly $600 million remaining on our previously announced share buyback authorization. Our approach to capital allocation remains the same, to opportunistically buyback shares to offset dilution from employee equity programs over time, while maintaining sufficient capital to deploy with strategic M&A presents itself.
Before I cover Q4 guidance, I want to provide a quick reminder about our typical four quarter dynamics and add some color to our two recent transactions with StackPath and Lumen. As in prior years, seasonality plays a significant role in determining our financial performance for the fourth quarter. Typically we see higher than normal traffic from large media customers and a pickup in seasonal online retail activity from our e-commerce customers. Both of these traffic patterns are difficult to predict.
Q4 also tends to have higher operating expenses than in Q3, driven by higher sales commissions due to accelerated payments for sales reps who overachieved their annual quotas. As it relates to the transactions with StackPath and Lumen, first, both transactions were acquisitions of selected CDN customer contracts, including over 200 net new customers to Akamai. We did not acquire any other assets or liabilities of either company. Second, we expect the two transactions combined will add approximately $17 million to $20 million of revenue in Q4. Third, we expect to record approximately $13 million to $14 million in StackPath and Lumen TSA costs in Q4. These costs will be recorded in our cost of goods sold and will have a negative impact of approximately 1 percentage point on gross margin, adjusted EBITDA margin, and non-GAAP operating margin.
Combined, the StackPath and Lumen TSAs will negatively impact our Q4 EPS by approximately $0.06 to $0.07. We do not expect to incur any material TSA costs in 2024. And finally, our expectations for these customer acquisitions remain the same as we disclosed previously for the full year 2024. As a reminder, we expect the customer contracts acquired from StackPath to add approximately $20 million of revenue in 2024 and to be accretive to non-GAAP earnings per share by $0.03 to $0.05, and we expect the customer contracts acquired from Lumen to add approximately $40 million to $50 million of revenue in 2024 and to be $0.08 to $0.12 accretive to non-GAAP EPS.
With all that in mind, we are now projecting fourth quarter revenue in the range of $985 million to $1.005 billion, or up 6% to 8% as reported and in constant currency over Q4 2022. At current spot rates, foreign exchange fluctuations are expected to have a negative $8 million impact on Q4 revenue compared to Q3 levels, and a positive $2 million impact year-over-year.
Taking into account the impact of the StackPath and Lumen TSAs, for the fourth quarter, we expect cash gross margins of approximately 72%. Q4 non-GAAP operating expenses are projected to be $305 million to $311 million. We expect Q4 adjusted EBITDA margin of approximately 41%. We expect non-GAAP depreciation expense to be between $123 million to $125 million and we expect a non-GAAP operating margin of approximately 29% for Q4.
Moving on to capex, we expect to spend approximately $143 million to $153 million, excluding equity compensation and capitalized interest in the fourth quarter. This represents approximately 15% of our projected total revenue for the fourth quarter. Additionally, our capex guidance includes the integration requirements to support the traffic for both CDN customer contract acquisitions.
Based on our expectations for revenue and cost, we expect Q4 non-GAAP EPS to be $1.57 to $1.62. This EPS guidance assumes taxes of $50 million to 52 million based on an estimated quarterly non-GAAP tax rate of approximately 17%. It also reflects a fully diluted share count of approximately 155 million shares.
Looking ahead to the full year, we have increased revenue to a range of $3.802 billion to $3.822 billion which is up 5% to 6% year-over-year as reported and 6% in constant currency. At current spot rates, our guidance assumes foreign exchange will have a negative $18 million impact on revenue in 2023 on a year-over-year basis. We are raising our security revenue growth expectations to approximately 15% for the full year 2023, and we continue to expect to achieve approximately $0.5 billion in revenue from compute in 2023.
Despite a year of significant investment, we are estimating non-GAAP operating margin of approximately 29%. With all that in mind, we have raised our estimated non-GAAP earnings per diluted share to a range of $6.08 to $6.13. Our non-GAAP earnings guidance is based on a non-GAAP effective tax rate of approximately 17%, and a fully diluted share count of approximately 155 million shares. Finally, our full year capex is expected to be 19% of total revenue.
In closing, we are very pleased with how the business is performing in 2023 as we continue to invest for revenue growth and improve our profitability.
With that, we now look forward to your questions. Operator?