The Browser As Sandbox

A "browser sandbox" isolates pages and scripts in a restricted environment. This can prevent malicious sites from accessing your files and doing other dangerous things on your machine.

Modern browsers run rendering and JavaScript execution in low privilege processes, with a separate "broker process" (or "mediator process") controlling access to system resources (process isolation)  Renderer processes cannot read files, launch programs or interact with other applications.

Types of browser sandboxing include local sandboxing - where the sandbox is built into browsers (Chromium, Firefox, Safari), remote/cloud sandboxing where websites are run in isolated VMs streamed to your machine, and online URL sandboxes (services like Browserling which allow you to open URLs in disposable remote browsers).

Browser sandboxing is a foundational security layer in modern browsers and remote isolation platforms.