Firefox 153: checking local network access

A more visible boundary

Released on 21 July 2026, Firefox 153 enables Local Network Access restrictions by default. Sites must request permission before connecting to local devices or services.

Identify affected uses

For an interface communicating with nearby equipment, we would first document the actual request path. Which page initiates the connection, to which address and for what action? This record avoids incorrectly blaming the device or server for a failure.

Then examine the user journey when permission is accepted, refused or already remembered. The interface should explain the expected action in task-related language: contacting equipment, reading a status or sending a document.

Keep causes distinguishable

We recommend separating permission, transport and authentication errors. Each needs a different explanation. Testing a powered-off device also remains necessary: authorization does not establish availability. For local tools, this change primarily encourages an explicit, verifiable connection journey.

Official source.

Retrospective watch — July 2026.