You can finally control serial devices from Firefox

What happened

Firefox is getting native Web Serial support. It has been reported that Firefox Nightly 151.0a1 added the Web Serial API around April 13, bringing the long‑gestating feature to Mozilla’s development channel after more than a decade of discussion. No official documentation has appeared yet, and activating the capability reportedly requires flipping a flag in the Nightly menu — so don’t expect a polished experience just yet.

What Web Serial does

Web Serial lets a browser speak directly to devices that use serial ports — think 3D printers, Arduinos, ESP32s and other microcontrollers, plus devices that emulate serial over USB or Bluetooth. Google Chrome introduced its implementation in 2021, and Chromium‑based browsers like Edge, Opera and Vivaldi have supported the API since. For developers and tinkerers who’ve waited to control hardware from the web, this is that satisfying click of a long‑stuck lock finally giving way.

Why it mattered (and why Mozilla hesitated)

Mozilla’s caution has a backstory. Security and privacy concerns — notably Martin Thomson’s 2020 argument that physical serial access can confer undue trust and privilege — stalled adoption. It has been reported that by 2024 Firefox leadership was open to shipping Web Serial behind an add‑on or gating mechanism if consent text could be made clear. Mozilla still resists WebUSB and WebHID, and Apple’s WebKit team echoes similar worries about fingerprinting and security. So this move isn’t reckless; it’s a compromise shaped by debate and delay.

Why you should care

This isn’t just about hobbyists firing up a 3D printer from a tab. It’s another data point in a larger tug‑of‑war: user convenience versus platform risk, and the pressure on browsers to support devices lest users migrate to Chrome’s ecosystem. It has been reported that the initial Web Serial commit landed in mid‑January, with more polishing to come. Expect bugs, expect tweaks — and yes, expect a small army of makers to celebrate. Who wins? Probably the users — finally, a browser choice that doesn’t mean giving up your gadget workflow.

Sources: The Register