How Does WiFi Actually Work?

WiFi is just radio. Your router converts internet data into electromagnetic waves at 2.4, 5, or 6 GHz and broadcasts them to your devices, which translate the waves back into bytes. The current top WiFi 7 standard can shovel up to 46 Gbps over the air — about 30,000× faster than the original 1997 WiFi.

It's not magic. It's the same principle as AM radio with vastly better packaging.

Step 1: data becomes a signal

When your phone requests a webpage, the request is binary — a string of 1s and 0s. Your router takes those bits and modulates them onto a carrier radio wave. Modern WiFi uses OFDM (Orthogonal Frequency-Division Multiplexing), which splits the carrier into hundreds of tiny sub-channels and sends bits across all of them in parallel.

OFDM is also how 4G, 5G, and digital TV work. Same trick.

Step 2: the antenna broadcasts

Your router's antenna oscillates electrons at gigahertz frequencies, generating an electromagnetic wave that radiates outward. The wave is invisible but real — same family as light, just at a much lower frequency.

Wave moves at the speed of light. Across a typical home: about 30 nanoseconds.

Step 3: your device listens

Your phone's WiFi chip has its own antenna, tuned to the same frequencies. When the wave passes, it induces a tiny current in the antenna. The chip decodes that current back into the bits the router sent.

Two-way conversation: your device transmits the same way, on the same frequency, just lower power.

2.4 GHz vs 5 GHz vs 6 GHz

WiFi uses three bands. Each has trade-offs:

• 2.4 GHz: Lower frequency, longer wavelength. Travels far, passes through walls well. But crowded — same band as Bluetooth, microwaves, baby monitors.
• 5 GHz: Faster. Less interference. But shorter range and worse wall penetration.
• 6 GHz (WiFi 6E and 7): Newest band. Massive bandwidth, low congestion. Even shorter range than 5 GHz.

Your router and devices auto-pick the best band based on signal quality.

Why your microwave kills WiFi

Microwave ovens vibrate water molecules at 2.45 GHz — almost exactly the same frequency as 2.4 GHz WiFi. A leaky microwave dumps stray radiation into your network's band. Bluetooth headphones and old cordless phones share the same band too.

Switching to 5 GHz makes the microwave problem disappear.

Why distance kills speed

Radio waves spread out spherically. The signal strength at any point falls with the inverse square of distance — double the distance, get 25% the signal. Below a certain threshold, your device drops to slower modulation schemes to keep the connection alive. That's why 200 ft from your router feels like dial-up.

Walls, especially metal and water-rich materials (people, fish tanks), absorb signal hard.

Channels and interference

Each WiFi band is divided into channels. 2.4 GHz has 11 channels in the US, but only 3 don't overlap (1, 6, 11). Pick a crowded channel and your router fights every neighbor's router. Most modern routers auto-select the cleanest channel, but you can override it manually.

Why WiFi 7 is so much faster

Three things. Wider channels (320 MHz vs older 80 MHz). Higher modulation (4096-QAM packs more bits into each symbol). And Multi-Link Operation, which lets your device use multiple bands at once — receive on 6 GHz, transmit on 5 GHz simultaneously.

The future: WiFi 8

Already in standardization. Targets 100 Gbps and dramatically lower latency for VR/AR. Expected ratification: 2028. Your router today probably won't support it.

Want more "how it works" reads? See how fast light travels or why the sky is blue.