Fastly (FSLY) Q3 2025: Security Revenue Jumps 30% as Platform Cross-Sell Accelerates
Fastly’s Q3 delivered record results, propelled by a 30% surge in security revenue and disciplined operational execution. The company’s platform-led cross-sell strategy is translating into tangible gains, with margin expansion and free cash flow reaching new highs. Management’s raised guidance signals confidence, but investors should watch for normalization following a strong quarter fueled by early bookings and a major top 10 customer win.
Summary
- Security Momentum: Security products now comprise a record share of revenue, validating Fastly’s platform expansion.
- Cross-Sell Execution: Major wins with top customers highlight the effectiveness of multi-product adoption.
- Margin Leverage: Margin gains and cash flow improvements indicate operating discipline is taking root.
Performance Analysis
Fastly posted its third consecutive quarter of accelerating revenue growth, with total revenue up 15% year-over-year to $158.2 million, surpassing the high end of guidance. Security revenue was the standout, climbing 30% year-over-year to $34 million and now representing 21% of total revenue—a new high for the segment. Network services, Fastly’s core content delivery and edge cloud business, grew 11% year-over-year, while “other” products (primarily compute) rose 51% year-over-year off a small base.
Gross margin expanded to 62.8%, aided by a $1.6 million non-recurring cost reversal, but even excluding this, underlying margin performance was strong at 62%. Operating income reached $11.6 million, and free cash flow swung to a record $18.1 million, reflecting improved cost discipline and operating leverage as opex grew slower than revenue. The top 10 customers accounted for 32% of revenue, with notable expansion from a major cross-sell, but revenue growth outside the top 10 (17% YoY) signals broad-based health.
- Security Outperformance: Security revenue’s share of total sales hit 21%, up sharply from prior periods, underpinned by new product uptake and a major cross-sell win.
- Margin Expansion: Gross margin improvement reflects both scale and network efficiency investments, not just one-time items.
- Cash Flow Turnaround: Free cash flow improved by $25.2 million year-over-year, a key milestone for sustainability.
Net retention rate (NRR) improved to 106%, and management expects further gains as cross-sell and upsell initiatives mature. Overall, the quarter’s outperformance was driven by a combination of broad-based execution and a timely boost from early bookings and a large customer expansion, suggesting Q4 growth may moderate sequentially.
Executive Commentary
"This quarter marks the next step in Fastly’s transformation, accelerating growth and innovation with operational rigor and discipline. As a result, we are raising our full year guidance for revenue, profitability, and free cash flow."
Kip Compton, Chief Executive Officer
"Revenue for the third quarter increased 15% year-over-year to $158.2 million... This revenue upside was driven by three key factors. First, successful cross-sell motion... Second, competitive share gains through new customer acquisition. And finally, greater upsells with existing network services customers."
Rich Wong, Chief Financial Officer
Strategic Positioning
1. Platform Cross-Sell and Upsell Execution
Fastly’s platform strategy—offering delivery, security, and compute services as an integrated solution—continues to gain traction. The quarter saw a major multi-product win with a top 10 customer, now using all three product lines. This validates Fastly’s push for account consolidation, driving both higher ARPU (average revenue per user) and stickier relationships.
2. Security Product Momentum
The security business is now Fastly’s fastest-growing segment, fueled by new offerings like next-gen WAF (web application firewall), API discovery, and AI-driven bot management. Management cited broad-based demand across security SKUs, not just a single product, and highlighted that growth would have been robust even excluding the large cross-sell win.
3. Margin and Cost Discipline
Operating leverage is emerging as a durable theme, with opex up just 10% year-over-year against 15% revenue growth. Network efficiency improvements and disciplined spend are driving gross margin gains, with further upside possible as new CFO Rich Wong implements more rigorous ROI frameworks and budgeting.
4. International Expansion
Fastly is targeting international markets, particularly APJ (Asia-Pacific Japan), through increased sales coverage and local leadership hires. Early wins in the region are starting to show up in results, but management frames this as a sales-driven strategy rather than a heavy infrastructure investment, with returns expected to accelerate into 2026.
5. Customer Base Diversification
No single customer represented more than 10% of revenue, and growth outside the top 10 customers remains strong. This reduces concentration risk and reflects successful penetration into a broader set of enterprise and mid-market accounts.
Key Considerations
Fastly’s Q3 results reflect a confluence of strategic execution, favorable market dynamics, and a few non-repeatable boosts. Investors should weigh the sustainability of these drivers as the company enters Q4 and 2026.
Key Considerations:
- Security Growth Durability: Security’s 30% growth was aided by a major cross-sell, but underlying demand remains robust even when excluding the largest deal.
- Sequential Growth Normalization: Q3 benefited from early bookings linearity and a large full-quarter customer ramp, setting a high bar for Q4 sequential gains.
- Margin Sustainability: Gross margin expansion is attributed to both scale and engineering-driven network efficiencies, but one-time cost reversals will not repeat.
- International Upside: Early APJ wins suggest international expansion is beginning to contribute, though the impact is not yet material to the overall business.
- Competitive Landscape: Share gains from competitors like Edgio are moderating, and incremental upside from smaller players (e.g., Quilt) is expected to be limited.
Risks
Fastly’s consumption-based revenue model introduces inherent quarterly variability, especially as traffic patterns and customer usage can fluctuate. While security growth is strong, it remains partly exposed to large deal timing, and the normalization of Q3’s unique boosts could temper near-term momentum. Ongoing competitive pressure and macro uncertainty in digital media and retail verticals add further risk to the growth trajectory.
Forward Outlook
For Q4 2025, Fastly guided to:
- Revenue of $159 to $163 million, representing 15% annual growth at the midpoint
- Gross margin of 61.5% plus or minus 50 basis points
- Non-GAAP operating profit of $8 million to $12 million
For full-year 2025, management raised guidance:
- Revenue of $610 to $614 million (13% YoY growth at midpoint)
- Gross margin of 60% to 61%
- Operating profit of $9 to $13 million (2% margin at midpoint)
- Free cash flow of $25 to $35 million (up $66 million YoY at midpoint)
Management highlighted that all ByteDance (TikTok) revenue is included in guidance, with U.S. traffic representing less than 2% of Q3 revenue. They expect continued momentum from cross-sell and upsell, but Q3’s early bookings and customer ramp will not recur in Q4.
- Bookings linearity and strong Q3 customer ramp set a high comparison base
- Gross margin expected to remain elevated due to network efficiency
Takeaways
Fastly’s Q3 demonstrates that its platform and security-led strategy is working, with operating discipline and customer diversification adding resilience. However, investors should anticipate more normalized sequential growth ahead, as some Q3 tailwinds fade.
- Platform Stickiness: Multi-product adoption is driving higher retention and wallet share, supporting the company’s long-term transformation goals.
- Margin and Cash Flow Inflection: Gross margin and free cash flow gains validate recent cost and engineering investments, but sustainability will be tested in coming quarters.
- Future Watch: Track security revenue growth ex-large deals, international sales contribution, and whether new cross-sell wins can offset the normalization of this quarter’s unique boosts.
Conclusion
Fastly’s third quarter marks a pivotal step in its evolution from CDN to edge platform, with security and cross-sell leading the way. Execution is improving, but the sustainability of recent momentum will be tested as one-off benefits fade and competition intensifies.
Industry Read-Through
Fastly’s strong security growth and cross-sell success underline a broader industry shift toward integrated edge-cloud and security platforms, as enterprises prioritize vendor consolidation and developer flexibility. CDN peers and cloud security providers should expect continued pressure on single-product offerings, and those with robust cross-sell and international go-to-market strategies are positioned to outperform. Margin expansion driven by network efficiency and disciplined spend is likely to become a key differentiator across the edge and cloud infrastructure sector, with investors rewarding operators who can translate traffic growth into sustainable profitability.