Why does my DJI drone keep losing signal or disconnecting?

A DJI drone usually loses signal because something is between it and the controller: trees, buildings, a hill, or even your own body if the drone is behind you. Radio interference in cities and controller antennas pointed the wrong way are the next most common causes. Keep a clear line of sight, fly higher than nearby obstacles, face the flat side of the antennas toward the drone, and use the Auto channel. If the drone won't fly far even in the open, check its distance limit settings.

What blocks a drone signal — Signal loss figures from DJI's help center (tree canopy 5 to 10 dB, dense forest over 30 dB). Every 6 dB of loss halves your range, so 30 dB cuts it to about 1/32.

Why the signal drops

DJI's help center explains that range falls fast with obstructions. Every 6 dB of signal loss halves the distance. DJI's figures:

A single tree canopy: 5 to 10 dB
Your body, with the drone behind you: about 10 dB
A reinforced concrete wall: about 30 dB
Dense forest: more than 30 dB

With 30 dB of loss, DJI's example shows an 8 km link shrinking to about 250 m. Haze, high humidity and cloud make it worse. At long distances the line of sight gets close to the horizon, so tree lines and rooftops start blocking the signal even if they look small.

Fixes

Keep line of sight and stay higher than nearby trees and buildings. DJI's first fix for a frozen picture is to climb above the obstacle.
Face the antennas toward the drone. DJI says the plane of the antennas should face the aircraft. With the Mini 4 Pro's DJI RC 2, DJI says the best zone is with the antennas at 180° or 270° to the back of the controller.
Turn around. Don't fly the drone behind you.
Reduce interference. Use Auto channel under ··· > Transmission in DJI Fly. DJI says not to use other wireless devices on the same frequencies next to the controller. Turn off phone hotspots nearby.
Update firmware for the drone and controller.
Check for damage. A controller that keeps reporting signal errors in open fields may have a hardware fault. DJI says to send it in.

Why won't my drone fly far?

If it stops at a fixed distance with full signal, it's a limit, not range. DJI lists these causes:

A Max Distance set in Safety settings
Beginner or tutorial mode
A weak GPS signal
Flying in a restricted area or altitude zone
Not signed in to a DJI account

The Neo in phone or palm control is capped at 50 m distance and 30 m height. See DJI altitude and distance warnings.

What the drone does when it loses signal

Your Signal Lost setting decides. With Return to Home set and a Home Point recorded, the Mini 3 starts Failsafe RTH after the controller signal has been lost for more than 11 seconds. It first flies back 50 m along its route, then climbs to the RTH altitude and heads home. If video drops but control remains, DJI Fly prompts you to start RTH. Set the RTH altitude above every obstacle before you take off. See DJI Return to Home not working.

Mini 3 losing signal

The Mini 3 uses DJI's O2 transmission, rated at 10 km (6.2 mi) under FCC rules in ideal conditions. Real flights are shorter around trees and buildings. If yours drops early, check antenna direction first, then the phone cable on the RC-N1.

If you need more range, a newer drone with O4 transmission helps, such as the Mini 4 Pro. How the systems compare is in how DJI video transmission works.