Forgot your password?
typodupeerror
Firefox Build

Mozilla Brings Web Serial Workflows to Firefox, Collaborates With Adafruit (mozilla.org) 15

The Web Serial API lets websites write to (and read from) serial devices using JavaScript, including USB and Bluetooth devices with virtual serial ports. And this week's Firefox 151 release introduced support for the Web Serial API on desktop.

"Most folks won't use this API," acknowledges Mozilla's blog, "but for our community of builders and tinkerers, it unlocks the ability to use Firefox to communicate directly with compatible hardware devices like microcontrollers, development boards, and other serial-connected devices..." With Firefox's browser engine, Gecko, now supporting Web Serial, users can now connect, code, configure, and control compatible hardware directly from the browser in many workflows, often without additional software or complicated setup...

As part of this week's launch, Adafruit, one of the internet's most beloved open-source hardware communities, is collaborating with us to test and validate what browser-based hardware development can look like in Firefox with Web Serial support... With Web Serial support in Firefox 151, Adafruit's browser-based hardware workflows now work directly in Firefox as well, with no additional software or complicated setup required for many projects. We invite you to give it a try...

We want the web to be open, flexible, and shaped by the diversity of people building on it. If you're wiring up your first board, experimenting with hardware projects, or dusting off an old electronics kit, give Adafruit and Web Serial in Firefox a try. Build something amazing. Make something useful. Tell us what works. Tell us what breaks. Most of all, make it your own.

Mozilla's "Hacks" blog demonstrates with an Adafruit ESP32-S2 based board "where messages sent from web code can be directly displayed on the device over Web Serial."

And Mozilla engineer Alex Franchuk even built a handheld device that changes a web page's CSS properties.

Mozilla Brings Web Serial Workflows to Firefox, Collaborates With Adafruit

Comments Filter:
  • This Is Great News (Score:5, Interesting)

    by crunchy_one ( 1047426 ) on Sunday May 24, 2026 @04:15PM (#66158780)
    Now I can dump Chrome in the trash where it belongs. Web Serial support was the sole reason I've kept it on my machines.Thank you Mozilla, thank you Adafruit!
  • This is great. (Score:4, Insightful)

    by Kamineko ( 851857 ) on Sunday May 24, 2026 @04:25PM (#66158790)

    I do love it when malware advert javascripts can upload random new firmware updates into my mouse and keyboard turning them into stealth keyloggers. This is great.

    This feels like when Flash sandbox breaks became a thing, but worse. At least in those days we got smooth fullscreen vector animations and games to enjoy. I'd rather Flash had just been bloody fixed instead of browsers themselves becoming Shit Flash But Holy Cow It Runs Worse And Gets Worse.

    • by znrt ( 2424692 )

      I do love it when malware advert javascripts can upload random new firmware updates into my mouse and keyboard turning them into stealth keyloggers. This is great.

      so you're using a serial mouse in 2026 to browse porn? that's so "cool"!!

    • You'd get a popup to choose the port and grant permissions.

      Have you ever flashed a Meshtastic or ESPHome device or updated firmware on a radio transceiver?

      That's what they're talking about here.

  • It had better be disabled by default.

    • It requires permissions just like accessing a camera or microphone. Stop being paranoid.
      • It's still a new code base and one that can access hardware so it's understandable that people would be nervous.

        At the very least it should probably be something that has to be enabled in settings. And maybe it does I haven't looked into it. There are too many examples of security vulnerabilities that can bypass permissions. That's what the grandparents is worried about
  • ...a way to freeze Internet explorer was by inserting a < img src=lpt1: > tag in the html code.

  • by mmiscool ( 2434450 ) on Sunday May 24, 2026 @05:34PM (#66158852) Homepage
    Sites like https://serialterminal.com/ [serialterminal.com] will work in firefox. It was like pulling teeth to finally get brave to support this also. Now the only one left is safari.
  • Because it's the first thing that comes to my mind: much easier support for client-side digital document signatures using token certificates (like thumbdrive or smartcard devices) plugged in the client machine.
    This has been a pain in both my previous and current job. Both provided SaaS products that worked with digitally-signed XML files. But when the client opted for using tokens/smartcards, we had no other choice than make the client install a client-side software to do it locally and send it back to the

"Floggings will continue until morale improves." -- anonymous flyer being distributed at Exxon USA

Working...