Firefox Community Forum

Since updating to Firefox 141.0 (Win11), I've had issues with performance and on-screen behaviour of dynamic web pages/sites. The problems do not manifest on Chrome, or on a reinstalled version of Fx 140.0.4 on the same computer running at the same time (and with copy of original profile's data files, extensions etc.), they do manifest on a new Firefox 141.0 profile with only one tab open.

The problem happens on dynamic pages (e.g. gmail.com, boardgamearena.com/lobby) but doesn't seem to happen on static pages. Note that this doesn't depend on page elements moving around the visible window (e.g. panels opening and closing).

The manifesting problems:

• Screen pointer rapidly switching between standard arrow pointer, mouse with index finger (clickable link) and serifed-style insertion bar, even when positioned on a part of the page that is not a link or a text box. Video (MP4, <1MB) showing behaviour at https://imgur.com/a/absjTh4.
• Browser intermittently fails to respond to browser actions (mouse clicks, keyboard entry)
• Small increase in browser CPU usage

Problem is worse if general CPU usage (from other applications) is already high - low CPU usage reduces but doesn't eliminate the problem. (Established by changing my BOINC settings and/or snoozing BOINC and observing; I have a gadget that monitors CPU and other resource usage.)

The fact that I can see the problem occurring on Fx 141 but have Fx 140.0.4 working fine at the same time on the same page, suggests that this is a Fx 141 issue. Regular malware scanner and an alternate found no issues.

Happy to do more diagnostic testing if it's helpful.

Description: We have encountered a significant performance issue with NativeMessaging API in Firefox when an extension communicates with a native application.

In scenarios where many objects must be enumerated (e.g., ~458 certificates), Firefox is dozens of times slower than Chromium-based browsers.

Environment:

Firefox (latest stable, reproduced in 2025)

Windows 11 x64

Same machine and same native plugin tested in Chrome, Edge, Yandex Browser

Steps to Reproduce:

Create a WebExtension that communicates with a native application via NativeMessaging.

Perform enumeration of a large number of objects (≈ 450–500).

Measure execution time in Firefox vs Chromium.

Actual results:

Firefox: enumeration of 458 objects takes ~2 min 30 sec

Chromium/Edge/Yandex Browser: enumeration of the same 458 objects takes ~5 sec

Additional tests: Round-trip time (RTT) for a single message:

Firefox: ~73.7 ms

Chromium: ~0.3 ms

Because the extension and the plugin exchange a large number of messages, this performance gap becomes critical.

Expected results: NativeMessaging API in Firefox should perform at a level comparable to Chromium browsers, so that extensions relying on heavy message exchange remain usable.

References: Bug 1288912 – Native messaging performance is extremely poor

Although this bug is marked as resolved, performance testing still shows a major discrepancy in the current versions of Firefox.

Question: Is there any ongoing work or plan to optimize the implementation of NativeMessaging API in Firefox to address this performance issue?

After the latest update (142) the only button that you can click is the home that will work. The address bar and search and nothing else will do anything. What is causing this? Thanks

Hello For some reason most of the buttons in my toolbar have stopped working. When I first open Firefox they all work, then when I enter websites they stop working. The 'home' button still seems to work, but almost all others (such as the 'back' button etc) can't be selected. This is very frustrating. To note, I am not tech savvy at all.

Thank you in advance for your help.

Andrew