How do I fix Bluetooth that will not connect?

Bluetooth stores a pairing record at both ends. If one end loses or corrupts its record they disagree, and the connection fails in ways that look like hardware failure. Deleting both records and starting again resolves the majority of cases.

What you'll need

• Both devices
• The device's manual for its pairing button (optional)

Step by step

1. Forget or remove the device from your phone's Bluetooth list.Not just disconnect — remove it entirely, so the stored pairing record is deleted.
2. Put the accessory back into pairing mode.Usually holding its power or pairing button until a light flashes. Headphones often need them in the case, or a long press.
3. Turn Bluetooth off and on again on the phone.It clears the adapter state before you attempt a fresh pairing.
4. Pair from close range with nothing else connected.Within a metre, and disconnect other Bluetooth devices. A phone already connected to a watch and a car may refuse another connection.
5. Check it is not connected to something else.Headphones paired with a laptop, tablet or second phone will connect to whichever is nearest and on. This is the most-missed cause by a distance.
6. Charge both devices.Low battery causes flaky Bluetooth well before the device shuts down.
7. Restart the phone if it still fails.It resets the Bluetooth stack, which occasionally gets stuck in a state no amount of re-pairing clears.
8. Reset the accessory to factory defaults as a last step.Most headphones and speakers have a reset sequence in the manual. It clears every stored pairing at their end.

Tips

• Most accessories remember several devices but connect to only one at a time. Turning off the other device is often the whole fix.
• Bluetooth and 2.4GHz wifi share a frequency band. In a congested area, interference causes dropouts that look like a fault.
• Car systems often have a limit on stored phones. When it is full, new pairings silently fail until you delete an old one.

Common mistakes

• Pairing again without forgetting first — The corrupted stored record remains and the new attempt inherits the same problem.
• Forgetting the device on only one side — Both ends store a pairing. Clearing one and not the other leaves them disagreeing.
• Assuming the accessory has failed — A stale pairing or a connection to another device explains most cases and costs nothing to rule out.

Questions people ask