01. Purpose and design
Tor Browser is built to route browsing through Tor and reduce common forms of tracking. It incorporates privacy-oriented defaults and anti-fingerprinting measures intended to make users' browsers more similar to one another.
02. Security levels and compatibility
A more restrictive security level may disable or limit JavaScript, fonts, media, and other browser features. A resilient website should therefore keep its essential content in semantic HTML, use ordinary links, and avoid making navigation depend on scripts. System fonts and strong color contrast help preserve readability.
03. Avoid unnecessary customization
Adding extensions, changing many browser settings, or installing unusual fonts can make a browser more distinctive. Privacy tools often work best when users avoid unnecessary modifications and keep software current.
04. Downloads and documents
Opening downloaded documents in external applications can reveal information outside the browser's protections. Consider whether a file is necessary, keep software updated, and use appropriate isolation for untrusted files.
05. A sensible checklist
Use official distribution channels, install updates promptly, avoid unknown add-ons, check that sensitive sites use HTTPS, and never assume that network privacy protects an account after signing in. See online privacy and browser fingerprinting.
06. Browser configuration is part of the security model
Tor Browser is designed to reduce the amount of identifying information a browser exposes and to make users’ browser characteristics more alike. Its protections depend on the bundled configuration. Installing extensions, changing advanced preferences without understanding their effects, or using a separate browser profile for sensitive activity can create distinctive signals or bypass expected routing.
Security levels trade compatibility for attack-surface reduction. A stricter level may disable or limit some web features, which can make sites less convenient but can reduce exposure to certain active content. The right setting depends on the threat model; no setting makes a compromised device safe.
07. Safer everyday use
- Download Tor Browser only from the official Tor Project download page.
- Install updates promptly; browser and security fixes matter.
- Avoid adding extensions. They can alter fingerprinting characteristics and may introduce risky permissions.
- Do not maximize assumptions: signing into a personal account still identifies that account to the service.
- Use HTTPS and treat files downloaded from unknown sources as untrusted.
08. Documents and external applications
Opening documents outside the browser can expose the device’s ordinary network connection or reveal metadata. If a document is sensitive, consider whether it needs to be opened at all, whether a safer offline workflow exists, and whether the application is configured to avoid remote content retrieval. Do not assume that a file inherits the browser’s network protections.
Primary reading: Tor Browser Manual and Tor Project Support. Last substantive review: 11 November 2026.