Introduction
Lightning Web Security is the current security architecture for Lightning Web Components and Aura components. In most orgs, the real design question is not whether security matters. It is whether your existing component portfolio is ready for the newer model and how you should test the transition.
How it compares to Locker
Salesforce documents that LWS supports features Lightning Locker does not, including better support for components importing components or modules from other namespaces and direct access to globals such as window, document, and element with LWS protections applied.
- Each namespace gets its own JavaScript sandbox.
- Cross-namespace communication is virtualized by the security architecture.
- The programming model is meant to be more transparent than Locker’s wrapper-heavy behavior.
How to evaluate impact
- List the custom Lightning components in the org.
- Identify whether they are local or managed-package based.
- Test critical pages, utilities, and cross-namespace behavior.
- Review any known compatibility constraints in the LWS docs before full rollout.
Example scenarios
If an org has no custom Lightning components, Salesforce explicitly notes that Lightning Web Security does not affect that org. If the org does have custom components, the most important validation areas are mixed namespace usage, third-party library behavior, and legacy Aura assumptions.