Performance decrease in my web app when Bitwarden browser extension is installed

[cadilhac]

Description

I am the developer of a web app. I am testing a new feature of my app and it appears it has some degraded performance when Bitwarden extension is installed. This happens in all browsers I have at hand (Brave, Chrome, Firefox, Edge). On Firefox, it's maybe a little less obvious, but still, perf is degraded.

I first removed all my browser extensions and put them back one at a time. At the end of this test, it was sure that Bitwarden was the culprit. Since I had the latest version, I decided to go back in time to ultimately find out that v2024.10.0 was not degrading my app but starting with v2024.10.1 the problem was happening. I tested other versions prior to v2024.10.0 and they are all fine. With different versions above v2024.10.0 I have the issue.

Obviously, I have no way to provide a repro. This happens in my app in development during a specific feature. When this happens, I am dragging an image file into the viewport and when hovering the viewport borders, the view scrolls many images (with heavy stuff happening like loading new images, decrypting them, displaying them, ...). The issue happens visually in the scrolling. It is choppy, struggling every a little less than 1 second. This gives: it scrolls smoothly during 600ms, then does it erratically during 100ms, then fine again during 600ms, then badly again, and so on (numbers are approximations).

It's as if, periodically during my dragover, bitwarden was processing something impacting the performance of the web page. It obviously starts with version 2024.10.1.

I guess it's not easy to investigate. But do you have an idea based on these details?

Operating System

Windows 10 22H2

Web Browser

Chrome, Brave, Microsoft Edge, Firefox

Browser Version

The latest ones at the moment of testing

Environment Versions

Version: any version from 2024.10.1 to current 2025.9.0
Server 2025.9.1

Issue Tracking Info

• I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

[bitwarden-bot]

Thank you for reporting this issue! We've added this to our internal tracking system.
ID: PM-26396

[pamperer562580892423]

Another user here.

Browser Version
The latest ones at the moment of testing

Environment Versions
Version 2024.10.1

If your extension version is 2024.10.1 then this is an old version and not the latest version.

[cadilhac]

If your extension version is 2024.10.1 then this is an old version and not the latest version.

As explained, the problem occurs from v20224.10.1 up to the current version (2025.9.0).

[NovaSilentium]

Hi there,

I attempted to reproduce your issue and was unable to do so. If the issue is isolated to certain devices, consider tuning your Key Derivation Function (KDF) iterations. Reducing iterations can improve login speed, while increasing them enhances resistance to brute-force attacks. If you lower the iteration count, ensure your master password remains strong (see https://bitwarden.com/password-strength/) and that Two-Factor Authentication is enabled (https://bitwarden.com/help/mfa/).

We use GitHub issues as a place to track bugs and other development related issues. If your issue persists, please write us back using our “Contact support” form located on our Help Center (https://bitwarden.com/help/).

You can include a link to this issue in the message content.

Alternatively, you can also search for an answer in our help documentation or get help from other Bitwarden users on our community forums (https://community.bitwarden.com/c/support/).

The issue here will be closed.

Thanks!

[cadilhac]

@NovaSilentium But I didn't mentioned I was logged in. I am not even logged in. Just the presence of the extension produces the issue. However, yes, it happens on my computer but not on another computer (same browsers, BW extension installed).
I'm puzzled by this...

[pghope]

I'm experiencing the same symptoms of reduced performance across all websites (generally choppy scrolling and CSS animations) whenever the Bitwarden extension is enabled in Version 2025.10.0.

I have replicated this in Firefox and Chrome (Windows 11) and on other machines. Performance returns to normal when the Bitwarden extension is disabled/removed, or downgraded to Version 2025.9.0.

Sounds like this may be linked to #14015 and #17090