Is Tampermonkey safe?
Tampermonkey modifies Content-Security-Policy headers on pages where userscripts are active and, when analytics are enabled, sends script install events to its own tracking server.
The extension rewrites or removes CSP headers across all HTTP/HTTPS pages to permit inline script injection whenever a userscript is scheduled to run. On partner userscript sites (greasyfork.org, tampermonkey.net, and others), page scripts can query the extension for the names and versions of installed userscripts via an internal message relay. If the user has opted into anonymous statistics, install, update, and remove events are reported to a.tampermonkey.net alongside a persistent random UUID.
Who publishes itJan Biniok - no other listings under this identity, 1 shared hostname
Jan Biniok - no other listings under this identity, 1 shared hostname
What this publisher told the store about itself, and the other listings that told it the same thing.
Shared hosts - 1 hostname
Hostnames hardcoded in this extension that few other listings call. That can mean one operator behind both, and it can equally mean a small shared vendor, so it is context rather than a conclusion. Hosts that many listings call are left out: they are services, not connections.
AI-generated. Findings may contain errors. Those marked Verified have been manually reviewed.
Publishers can request a review.
What it can do
Permissions this extension asks for, as declared in version 5.5.0. Asking for a permission is not a finding on its own - it is what the extension can do if it chooses to.
Read and change your data on every site you visit
<all_urls>
Schedule its own background tasks
alarms
Show you desktop notifications
notifications
See the address and title of every tab you have open
tabs
Detect when you step away from your computer
idle
See every page you navigate to, as you navigate to it
webNavigation
Watch every request your browser makes
webRequest
Watch, block and rewrite every request your browser makes
webRequestBlocking
Store an unlimited amount of data in your browser
unlimitedStorage
Store data in your browser
storage
Add items to the right-click menu
contextMenus
Write to your clipboard
clipboardWrite
Read and change cookies, including the ones that keep you signed in
cookies
Start, monitor and manage your downloads
downloads
Where it sends data
Destinations our analysis observed Tampermonkey contacting. Sending data somewhere is not a finding on its own - an extension that syncs your settings has to talk to its own server - but it is where your data can go, and who else it goes to.
- a.tampermonkey.net
Tampermonkey sends data to a.tampermonkey.net. 3 other extensions we have analyzed send data here.