# ESP32 Wi-Fi and Bluetooth together are unstable: share the radio and memory

> Fix drops when running Wi-Fi and Bluetooth together: they share one radio and much RAM, so reduce traffic, shorten tasks and consider two boards.

Canonical: https://roboticsengineering.in/fix/esp32-wifi-and-bluetooth-together-unstable/ | Published: 2026-11-03 | Updated: 2026-11-03

**Wi-Fi and Bluetooth share one radio and one antenna.** Running both heavily causes drops and slow transfers.

## What the message means

The chip switches the radio between them in time slices. Busy traffic on both, or low memory, leads to disconnects and resets.

## Fix it in this order

1. Reduce traffic on one of them, or use one at a time where you can.
2. Use BLE instead of classic Bluetooth, since it needs less memory.
3. Watch the free heap and avoid large buffers.
4. Keep the supply strong, as radio peaks are high.
5. Choose a partition scheme with enough room for both stacks.
6. Use a second board for one of the radios if the project needs both busy.

## Why it happens

The ESP32 has one 2.4 GHz radio shared by Wi-Fi and Bluetooth. Espressif’s documentation describes a coexistence scheme that time-shares the radio between them, so heavy use of both reduces throughput and can cause timeouts. Classic Bluetooth and Wi-Fi together also consume a large amount of RAM; BLE needs much less, which is why it is the usual choice when both are needed.

Radio transmit bursts pull a lot of current for a short time. A weak supply or a thin cable makes the voltage dip, and the chip then resets, which can look like a software fault. Watch the free heap over time to tell a memory problem from a power one.

## If you see this, do this

| You see | Do this |
| --- | --- |
| Wi-Fi drops when Bluetooth connects | Radio sharing. |
| Resets after a while | Memory. Watch the heap. |

## Related

[Wi-Fi keeps disconnecting](https://roboticsengineering.in/fix/esp32-wifi-keeps-disconnecting/), [web server heap](https://roboticsengineering.in/fix/esp32-async-web-server-crashes-ram-heap/).

Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.