Zscaler Internet Access (ZIA) CASB

Zscaler Internet Access delivers CASB as an inline capability within the Zero Trust Exchange, which means every byte of SaaS traffic is inspected at one of 150 plus global PoPs before reaching its destination. The Leader position in Gartner's SSE Magic Quadrant with the highest Ability to Execute reflects a platform that has proven this architecture at enterprise scale across thousands of large organisations globally. The IRAP assessment and AU data residency options make it one of the few SSE platforms formally suited for Australian government environments.

The limitation is that Zscaler CASB is a module within the ZIA platform, not a standalone product. Buyers must adopt the broader Zscaler architecture to access it.

The verdict: Zscaler ZIA CASB is right for large enterprises replacing VPN and proxy infrastructure with cloud-delivered SSE wanting CASB included natively. Organisations wanting standalone CASB without full SSE adoption should evaluate Microsoft Defender for Cloud Apps.

Last reviewed: May 2026

Strongest: Shadow IT visibility

Watch out for: Compliance reporting

Best for

Large enterprises replacing VPN with cloud-delivered CASB, SWG, and ZTNA in one Zero Trust Exchange.

Not suitable for: SMBs — minimum 250 users and enterprise pricing not justified at small scale.