Are Chrome Extensions Safe? Three Things to Check Before Installing
Check an extension’s site access, requested permissions and data handling explanations before installing. Learn what you can adjust afterwards and what store disclosures cannot prove.
Chrome extensions can be useful, but some can read web page content or change how your browser behaves.
A Chrome Web Store listing is not enough to decide whether to install one. Three checks can help you make that decision.
1. Which sites can it access?
Start with where the extension can work.
Before installing, check the store listing, the developer’s explanation and any installation warnings for its intended sites and access scope. Some extensions work across all sites; others target particular ones.
Broad access can be necessary, so “all sites” does not automatically mean dangerous.
Ask whether the scope makes sense for the extension’s function.
After installing, open “Manage extensions” in desktop Chrome, select the extension’s “Details” and check “Site access.” Depending on the extension, you can restrict access to when you click it or to specific sites.
2. What can it access?
During installation, Chrome may display warnings about the permissions an extension needs.
These can include access to information on pages you visit or to your browsing history.
A warning does not automatically mean an extension is dangerous, and no warning does not mean it is safe. Some permissions do not generate warnings.
The useful question is whether the requested permissions seem necessary for what the extension does.
If broad access seems unrelated to its purpose, pause before adding it and look for an explanation.
3. How does the developer say it handles data?
Check what the developer says happens to the information the extension reads.
Look at the Chrome Web Store’s privacy disclosures and the published privacy policy:
- What data does it handle?
- What is the data used for?
- Is it shared with third parties?
These are the developer’s published explanations. The store’s disclosures alone cannot prove that an extension makes no external network requests.
If the explanation is missing, vague or difficult to connect to the extension’s function, take time to clarify it before installing.
No single label establishes an extension’s safety.
Start with where it works, what it can access and how the developer says it handles data. These checks give you more to base a decision on than installing without looking.
Supplement: Legacy Tools also recorded network requests
On 16 August 2026, we recorded network requests in Chromium for the eight extensions Legacy Tools had published at that time.
Opening their options pages and popups produced 234 recorded requests. All accessed files inside the extensions; none went to external HTTP or HTTPS servers.
We tested local build outputs loaded on Linux (WSL2), not Google Chrome itself or the packages installed from the store. We did not include operations that run the extensions on actual web pages.
This result applies to the operations and environment we checked. It does not prove the absence of external traffic for every operation or future version.
Legacy Tools also publishes each tool’s permissions and external data transmission details on its technical transparency page.
Sources
- Google Chrome Web Store Help: Install and manage extensions.
- Google Chrome Web Store Help: Permissions requested by apps and extensions.
- Chrome for Developers: Declare permissions.
- Chrome Web Store: Program Policies.
These sources are external websites, checked on 13 September 2026. The network observations in the supplement are from 16 August 2026.