How do Wi-Fi blockers actually work?

Wi-Fi is radio, so a jammer transmits interference on frequencies the devices are using. If the interference is strong enough at the receiver, it has trouble picking out the real signal. Think of trying to follow a conversation in a very noisy room.

That can cause slow connections or disconnects. Radio jammers are illegal in many countries, partly because they can interfere with other communications too.

Physical blocking is different. A conductive enclosure, often called a Faraday cage, can reflect or absorb radio waves and weaken the signal passing through it. The metal mesh in a microwave door is an example of shielding.

How well it works depends on the enclosure and the frequencies involved. A random piece of metal won't necessarily block Wi-Fi completely.

Some devices described as blockers don't jam the radio signal at all. They send deauthentication messages that can make a Wi-Fi client disconnect. That's a different mechanism from filling the air with interference, and it doesn't physically shield anything.

A flaky connection doesn't automatically mean someone is using a blocker. Ordinary interference can also slow Wi-Fi down or cause drops. A Wi-Fi analyzer app may help show nearby networks and channel activity, though it won't necessarily identify every source of interference.