CASB functionality is no longer sold as a standalone product by most vendors. Instead, it's a core component of Security Service Edge (SSE) platforms. The market leaders—Netskope, Palo Alto Networks, Zscaler, and Microsoft—all deliver CASB as part of their broader cloud security platforms, which combine data protection, threat defense, and access control.
Key Takeaways
- The market has converged: Gartner stopped publishing standalone CASB reports in 2020. CASB is now evaluated as part of Security Service Edge (SSE) platforms.
- Multimode is standard: Leading solutions combine both inline (real-time inspection) and API-based (deep scanning of stored data) deployment methods.
- GenAI governance is critical: solutions must now detect shadow AI usage, differentiate between corporate and personal AI instances, and inspect prompts in real-time to prevent data leakage into public LLMs.
- User experience varies significantly, with performance, deployment complexity, and support quality differing substantially across vendors—often more so than in their feature sets.
- Total cost extends beyond licensing: Implementation complexity, operational overhead, and support quality significantly impact long-term TCO.
Understanding CASB in 2025
The CASB market has undergone significant evolution since 2020. That year, Gartner ceased publishing a standalone CASB Magic Quadrant and integrated this category into its SSE evaluations.
A platform that secures web traffic, SaaS applications, and private apps with one unified policy engine. That's what SSE delivers, with CASB as one of its four pillars:
- Secure Web Gateway (SWG) - Protects users from web-based threats
- Cloud Access Security Broker (CASB) - Secures SaaS applications and cloud data
- Zero Trust Network Access (ZTNA) - Provides secure access to private applications
- Firewall-as-a-Service (FWaaS) - Delivers cloud-native firewall capabilities
When evaluating CASB solutions in 2025, you're evaluating SSE platforms. The vendors listed in this article are presented based on their CASB and overall capabilities.
The Multimode Architecture Standard
Modern CASB deployments use two complementary methods:
API-Based (Out-of-Band)
- Connects directly to the APIs of cloud service providers.
- Scans data at rest within approved applications.
- Offers deep visibility into stored files and activity logs.
- Enforcement is retrospective, acting after policy violations occur.
Inline (Proxy-Based)
- Sits in the flow of traffic between users and cloud services
- Provides real-time inspection and policy enforcement
- Can block threats before they reach cloud applications
- Essential for controlling unsanctioned Shadow IT applications
Some vendors offer both methods on a single platform, as relying on one approach alone leaves significant security gaps.
The GenAI Security Challenge
Employees are using generative AI tools such as ChatGPT, Microsoft Copilot, and Google Gemini to enhance productivity. They're pasting source code, customer data, and strategic plans into public LLMs. That data then gets used to train the model, potentially exposing it to competitors or the public.
Any CASB platform you evaluate should provide:
- Discovery of all GenAI applications (sanctioned and shadow AI)
- Application control to differentiate between corporate and personal instances
- Real-time protection to inspect prompts and block sensitive data submission
CASB Vendors
1. Netskope
Leader in Gartner Magic Quadrant for SSE 2024, positioned furthest for "Completeness of Vision"; Leader in Forrester Wave SSE Q1 2024
Deployment Model: Multimode (inline proxy + API)
Netskope established its reputation through data protection capabilities. The platform offers coverage with the following characteristics:
- Over 3,000 data identifiers for content classification
- Inspection capability for more than 2,100 file types
- Real-time coaching for users that alerts employees before they share sensitive files.
- NewEdge network with direct peering to Microsoft and Google at every data center
The DLP engine goes beyond pattern matching to include fingerprinting and exact data matching. For GenAI governance, the platform can identify and control tools like ChatGPT and Microsoft Copilot with granular policies.
User Experience Insights:
Strengths reported by users:
- Visibility into SaaS usage and data flows
- Straightforward deployment process
- Knowledgeable support staff with deep product expertise
- Comprehensive CASB and DLP features
Challenges reported by users:
- Deep SSL inspection can cause latency and slow site loading.
- The platform experiences occasional stability issues.
- Some teams find the admin interface challenging to learn.
- Certificate-related complications for Python developers with strict validation requirements
Netskope user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
2. Palo Alto Networks (Prisma SASE / SaaS Security)
Leader in Gartner SSE Magic Quadrant 2024; only vendor named Leader in both SSE and SD-WAN Magic Quadrants; Leader in Forrester SSE Wave 2024.
Deployment Model: Multimode (inline + API, integrated with Next-Generation Firewall technology)
Palo Alto Networks delivers CASB as SaaS Security, a native service within Prisma Access built on the company's NGFW technology. This creates unified management through Strata Cloud Manager for organizations already using Palo Alto firewalls.
Platform capabilities include:
- Integrated SaaS Security Posture Management (SSPM): Offers one-click remediation for misconfigurations.
- Built-in User and Entity Behavior Analytics (UEBA): Establishes baselines for user behavior to detect suspicious activities.
- Machine Learning for Application Discovery: Leverages data from over 70,000 customers.
User Experience Insights:
Strengths reported by users:
- Offers comprehensive security features and threat protection.
- Provides a unified management console, particularly beneficial for existing Palo Alto customers.
- Designed for reliability and scalability, supporting large workforces.
- Features a single pane of glass for streamlined security operations.
Challenges reported by users:
- Complex initial setup and implementation process
- Steep learning curve requiring deep in-house expertise or professional services
- Customer support quality concerns
- Documentation is described as incomplete in some areas
Palo Alto Networks user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
3. Zscaler
Leader in Gartner SSE Magic Quadrant 2024; described as "the 800-pound gorilla of SSE" in Forrester Wave Q1 2024, with the highest scores for market presence, vision, and innovation
Deployment Model: Multimode (proxy-based + API)
Zscaler's architecture is built on its Zero Trust Exchange, a globally distributed, multi-tenant security cloud. It uses a proxy-based approach that terminates every connection, inspects all traffic, including full SSL/TLS decryption, and brokers new secure connections to destinations.
Platform capabilities include:
- Advanced Threat Protection with cloud sandbox for analyzing unknown files
- Cloud Browser Isolation providing agentless security for BYOD devices
- SSPM for continuous monitoring of SaaS application misconfigurations
- Integrated CASB service within Zero Trust Exchange for unified policy application
User Experience Insights:
Strengths reported by users:
- Users consistently report seamless expansion to over 40,000 users, highlighting the platform's stability and reliability at scale.
- The admin interface for policy management is intuitive and straightforward.
- The platform demonstrates strong performance with minimal latency.
- Users find basic administrative tasks easy to manage.
Challenges reported by users:
- Advanced policy configurations often necessitate specialized knowledge.
- Some deployments have encountered difficulties with Identity Provider integration.
- Certain areas of the API documentation are incomplete.
- The quality of technical support can be inconsistent..
Zscaler’s user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
4. Microsoft Defender for Cloud Apps
Widely deployed in Microsoft 365 environments; not included in the 2024 Forrester Wave due to early-stage SSE availability during the evaluation period
Deployment Model: Primarily API-driven, with endpoint integration achieved through Defender for Endpoint.
Microsoft Defender for Cloud Apps offers native integration with Microsoft 365 and Azure environments. It utilizes official vendor APIs to connect with and scan sanctioned cloud applications.
Capabilities include:
- Seamless operation with Microsoft Purview Information Protection for sensitivity label-based policies
- Shadow IT discovery via Defender for Endpoint, ingesting network traffic logs from Windows 10 and 11 devices
- Unified incident correlation as part of the Microsoft Defender XDR platform.
- Automatic correlation of alerts from Defender for Endpoint, Defender for Identity, Defender for Office 365, and Cloud Apps.
User Experience Insights:
Strengths reported by users:
- Seamless integration with Microsoft 365 and Azure.
- Proactive Shadow IT discovery powered by Defender for Endpoint.
- Rapid threat detection.
- Robust alert system for suspicious activities.
Challenges reported by users:
- Non-Microsoft application connections require additional manual configuration.
- The system generates a high volume of alerts, even for minor events.
- Performance issues or delays when accessing monitored applications.
- Admin portal accuracy concerns in some scenarios.
Microsoft’s Defender for Cloud Apps user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
5. Skyhigh Security (formerly McAfee MVISION Cloud)
Visionary in the Gartner Magic Quadrant for SSE 2024.
Deployment Model: Multimode (API, forward proxy, reverse proxy)
Skyhigh Security, a spin-off of McAfee's enterprise security business, has a legacy CASB. The platform supports over 40 applications, demonstrating extensive API coverage.
Platform capabilities include:
- Unified DLP engine with Exact Data Matching (EDM), Indexed Data Matching (IDM), and Optical Character Recognition (OCR)
- UEBA using machine learning to refine billions of events down to high-fidelity threats
- Mapping of detected activities to MITRE ATT&CK framework
- API processing engine detecting sensitive data in seconds
User Experience Insights:
Strengths reported by users:
- Gain comprehensive insights into all cloud applications in use.
- Utilize robust tools for threat detection and data analysis.
- Experience effortless integration with Microsoft Office applications.
- Benefit from a mature and stable platform designed to handle demanding enterprise workloads.
Challenges reported by users:
- Steep learning curve due to complex user interface.
- New admins may find the interface difficult to navigate.
- Occasional bugs and performance slowdowns have been reported.
- Delays in data reflection from integrated third-party tools are sometimes experienced.
Skyhigh Security user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
6. Cisco (Umbrella with Cloudlock Integration)
Included in Forrester SSE Wave 2024.
Deployment Model: Multimode (API-first + inline via Umbrella)
Cisco's CASB capabilities, acquired through CloudLock, are now integrated into Cisco Umbrella. This architecture leverages RESTful, API-based microservices for both Cloud DLP and UEBA.
Platform features include:
- An extensive library of pre-built policies to comply with regulations such as PCI and HIPAA.
- Advanced custom policy creation capabilities, leveraging regular expressions, data thresholds, and proximity controls.
- Machine learning-powered User and Entity Behavior Analytics (UEBA) for identifying anomalous activities.
- Security features, including impossible travel detection and country-specific access controls.
User Experience Insights:
Strengths reported by users:
- API-first architecture for easy deployment and scalability.
- Simple connection to leading cloud services.
- Seamless integration with the broader Cisco Security ecosystem.
Challenges reported by users:
- Limited granular control for specific use cases.
- Inability to create policies based on particular folders or file paths in some services.
- Reporting tools could be more comprehensive.
- Occasional bugs during operation.
Cisco’s Umbrella user feedback in this guide is aggregated from public review platforms, including Gartner Peer Insights, TrustRadius, G2, and community discussions, representing experiences reported by actual users of the platform.
Top CASB 2025 Capability Comparison Matrix
Additional CASB Solutions Alternatives
Forcepoint CASB
Deployment: Multimode (inline + API)
Forcepoint offers tight integration with its other products and supports Zero Trust access for unmanaged and BYOD devices. The platform includes web and content filtering, behavior-based monitoring, and API integration for cloud applications.
Fortinet (FortiCASB + FortiGate)
Deployment: Dual-mode (FortiCASB API + FortiGate/FortiProxy inline)
Fortinet employs a dual strategy for cloud access security, utilizing FortiCASB for API-based protection and leveraging FortiGate NGFWs along with FortiProxy for inline security. A key capability is tenant control, which enforces policies to limit users to their organization's sanctioned SaaS application instances.
Cloudflare (Cloudflare One)
Deployment: API-driven + inline via existing SWG/ZTNA
Cloudflare's CASB is part of the Cloudflare One platform. The architecture utilizes API integration for scanning data at rest, while leveraging existing SWG and ZTNA services for inline controls, eliminating the need for separate proxy configuration.
For organizations already utilizing Cloudflare's Zero Trust services, the platform's design prioritizes simplified deployment and management.
Lookout CASB
Deployment: Fully integrated SSE (CASB + ZTNA + SWG)
Lookout enhances its SSE platform with mobile threat defense, offering end-to-end Zero Trust encryption, UEBA, and Microsoft Azure Information Protection integration for sensitivity labels.
How to Choose the Right CASB/SSE Solution
Evaluate the Complete Platform, Not Just CASB Features
Assess the vendor's entire SSE offering. The strength of their SWG, ZTNA, and platform integration matters as much as individual CASB features. Organizations benefit most from unified policy engines and consolidated management interfaces.
Consider Your Existing Technology Ecosystem
Organizations deeply embedded in specific ecosystems (Microsoft, Palo Alto Networks, Cisco, Fortinet) should evaluate how well CASB integrates with existing tools. Native integrations often provide smoother operations and unified visibility compared to best-of-breed approaches requiring multiple management consoles.
Prioritize Your Primary Security Concerns
Different vendors have different areas of strength:
- Threat prevention: Palo Alto Networks and Zscaler provide robust threat detection and sandboxing
- Microsoft environment: Defender for Cloud Apps delivers unmatched native integration
- Email security: Proofpoint brings email threat intelligence to cloud security
Factor in Operational Realities
- Deployment complexity - Some platforms require significant professional services or in-house expertise
- Performance - Latency and reliability issues can impact user experience
- Support quality - Technical support responsiveness varies significantly across vendors
- Learning curve - Administrative interface complexity affects operational efficiency
Verify GenAI Governance Capabilities
- How the platform discovers shadow AI usage
- Differentiation between corporate and personal AI instances
- Real-time prompt inspection to prevent sensitive data submission
Calculate Total Cost of Ownership
Beyond license fees, factor in:
- Implementation and professional services costs
- Ongoing operational overhead and management burden
- Training requirements for security and IT teams
- Quality and responsiveness of vendor support
- Integration complexity with the existing security stack
Conclusion
The CASB market in 2025 looks fundamentally different from what it did five years ago. What started as standalone point solutions has been absorbed into comprehensive Security Service Edge platforms. This convergence isn't just vendor marketing—it reflects how cloud security actually works in modern enterprises.
Three themes emerge from the current landscape:
Platform integration matters more than individual features. The technical capabilities across leading vendors have reached rough parity. The differences that impact daily operations—deployment complexity, performance reliability, support responsiveness—often matter more than whether a vendor offers 3,000 or 3,500 data identifiers.
GenAI governance has moved from a future concern to an immediate requirement. Organizations can no longer ignore employees pasting sensitive data into ChatGPT and similar tools. Platforms without clear discovery, control, and real-time inspection capabilities for generative AI are already behind the curve in terms of threat mitigation.
User experience tells the real story. Marketing materials and analyst reports provide useful frameworks, but feedback from security teams actually running these platforms reveals operational realities that specifications don't capture. A feature-rich solution that requires constant troubleshooting delivers less value than a stable platform with slightly fewer capabilities.
The solutions profiled represent the current market as of October 2025. Cloud security continues evolving rapidly—platforms that address today's requirements while demonstrating clear roadmaps for emerging challenges provide the most sustainable value.
Frequently Asked Questions
Is CASB still relevant in 2025?
Yes. The functionality remains essential—organizations still need to secure SaaS applications, prevent data loss, and detect cloud threats. The delivery mechanism has evolved into Security Service Edge (SSE) platforms that provide CASB alongside web security and zero trust access, but the core capabilities are more important than ever.
What's the difference between CASB and SSE?
SSE is the broader platform; CASB is one component. SSE combines four pillars: Secure Web Gateway (SWG), Cloud Access Security Broker (CASB), Zero Trust Network Access (ZTNA), and Firewall-as-a-Service (FWaaS) into a single, cloud-delivered security platform. CASB specifically focuses on securing SaaS applications and cloud data.
Do I need inline or API-based CASB?
Modern deployments require both—that's why "multimode" has become the standard. API-based deployment provides deep visibility into sanctioned applications and data at rest, but acts retrospectively. Inline deployment provides real-time inspection and can block threats before they reach the cloud. Leading vendors offer both integrated platforms.
How do CASB solutions secure generative AI tools?
Modern platforms offer three key layers: discovery to identify all GenAI usage, including shadow AI; application control to differentiate between corporate and personal instances; and real-time, inline DLP to inspect prompts and block sensitive data submission before it reaches public LLMs.
