Tor Browser security slider, what each level actually disables
The shield icon at the top of Tor Browser hides three settings, three real changes to your attack surface, and one button that almost nobody flips on first use. Here is exactly what they do.
Tor Browser's security level slider exposes three discrete profiles — Standard, Safer, and Safest — each of which disables a successively wider class of features. Defaults are sensible for casual browsing on the clearnet but inadequate for darknet market access. Below is a feature-level breakdown.
| Feature | Standard | Safer | Safest |
|---|---|---|---|
| JavaScript | on | HTTPS only | off |
| Remote fonts | on | blocked | blocked |
| SVG & canvas | on | click-to-play | click-to-play |
| Audio / video | auto | click-to-play | click-to-play |
| WebGL | enabled | click-to-play | disabled |
For darknet market login screens the recommendation is unambiguous: slide to Safest and leave it there. Every Nexus Market page is designed to render correctly with JavaScript disabled. If a feature on the platform appears to require JavaScript, that is the platform doing something it shouldn't, and the conservative choice is to back out and report it.
What the slider doesn't change
Worth saying explicitly: the slider does not change which guard relay you use, does not change Tor's circuit isolation behaviour, and does not affect rendezvous-point selection on hidden services. It is a browser-level setting that disables foot-cannons in the rendering engine. For network-level OpSec the relevant settings live elsewhere — bridges, exit policy, and circuit isolation per-tab via the New Tor Circuit menu item.
Working Nexus Market mirrors
Below are the three v3 onion addresses currently serving the production market, signed with the platform's PGP key (fingerprint 0x7F2A0A9D). Use the Copy button — never retype an onion by hand.