A browser extension is effectively a mini-app running inside your browser. It can often read page content, observe form fields, and inject scripts. Treat installs like you’d treat giving someone a key.
The risk isn’t theoretical: many “helpful” extensions legitimately need broad permissions. The practical goal is to reduce your extension footprint, separate high-risk from low-risk, and make installs reversible.
What to check before installing
Extension preflight
- Permissions: does it request “read and change data on all sites”? If yes, be strict.
- Publisher: is it a known company, open-source project, or anonymous developer?
- Update cadence: does it receive regular updates with clear release notes?
- Reviews: scan for patterns (sudden rating swings, identical comments, “it started injecting ads”).
- Data handling: does the privacy policy explain what leaves your device?
Permission patterns (what they usually imply)
- “Read and change data on all sites”: can see most pages you visit and potentially modify them.
- “Access your browsing history”: can infer sensitive interests and behavior patterns.
- “Manage downloads”: can observe or influence downloaded files and filenames.
- “Access clipboard”: can read copied secrets (tokens, passwords) if you’re not careful.
Safer defaults that keep you productive
- Install fewer extensions; prefer built-in browser features when possible.
- Use a separate browser profile for “research tools” vs “personal accounts.”
- Remove extensions you don’t use weekly.
Operational hygiene (after you install)
Post-install routine
- Review permissions again after the first week (does it still need everything?).
- Disable on sensitive sites (banking, admin consoles) when possible.
- Watch for sudden UX changes (new banners, redirects, injected ads).
- Prefer “enable on click” for powerful extensions if the browser supports it.
Red flag: extension asks for more access than it needs
A PDF helper that requests “all sites” access is a mismatch. When permissions feel unrelated to the feature, assume risk is higher than advertised.