Open Bug 1675833 Opened 5 months ago Updated 5 months ago

Firefox Developer Edition doesn't recognize Control, Alt and Shift keyboard events


(Core :: DOM: Security, defect, P3)

Firefox 83





(Reporter: manker99, Unassigned)


(Blocks 1 open bug)


(Whiteboard: [domsecurity-backlog1])

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

Important notes: This works in other browsers and other editions of firefox, it seems like just the developer edition is affected. Tested in Version 83.0b9 (64-bit)

  1. I've entered the following code snipped into the developer tools console to log the keystrokes to the console:
    onkeydown = e => console.log(e.key);
  2. Now all keys I press get logged into the console

Actual results:

All keys I pressed got logged except for the Control, Shift and Alt key.

Expected results:

All keys should have been logged, including the Control, Shift and Alt key.

Component: Untriaged → DOM: UI Events & Focus Handling
Product: Firefox → Core

Here is a screenshot of the keyboard events of Firefox Developer Edition in Save Mode to make sure all Addons are disabled and Settings are reset (right) compared to a fresh installation of the new Microsoft Edge (left) on the website


I only see this with privacy.resistFingerprinting enabled, can you please confirm you have this enabled and that it works as expected when disabled?

Flags: needinfo?(manker99)

Yes, that was it, thank you! I remember setting this after reading about it on But should that be a feature? While I can imagine that it might be useful to prevent websites from tracking your keyboard input, this might break some things too (for example, in my case I couldn't use Shift to sprint in a browser game).

Flags: needinfo?(manker99)
Component: DOM: UI Events & Focus Handling → DOM: Security
Severity: -- → S4
Priority: -- → P3
Whiteboard: [domsecurity-backlog1]
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