A Hue accessory such as a dimmer switch or motion sensor talks to the Bridge over Zigbee, so an offline accessory is a Bridge, range or battery problem. First check the Bridge lights: Hue's article says the left light is power, the middle is network, the right is Hue's internet services and the round light shows a Zigbee signal, so if the Bridge is unhealthy no accessory will work. Then check the accessory's battery, since a weak battery makes a sensor look connected while it fails to report reliably, as independent guides note.
The checks in more detail
Replace the batteries with fresh ones of the right type. Check range: accessories should be within about thirty feet of the Bridge or of a mains-powered Hue light that relays the signal, and metal, thick walls and 2.4 GHz devices such as microwaves and routers weaken it; the dimmer reset article says to avoid placing it directly against large metal surfaces or near high-powered 2.4 GHz devices. Move the accessory or the Bridge, or add a Hue plug or bulb as a relay.
If the accessory is still offline, do a soft reset of a dimmer by holding all four buttons about five seconds, or re-pair it in the app. A factory reset is a last resort. Check the Bridge software is current. Write down which accessories dropped and when, since patterns by room or time often reveal a metal cabinet or a microwave. An accessory that drops only when a large appliance runs may be near interference, so move it a hand's width and retest.
Contact support with the model, battery type and Bridge lights ready. If two accessories in one room drop together, look at what sits between them and the Bridge, since one thick wall or a fridge can be the whole problem, and moving the Bridge a meter may fix both at once. Hue's reset guide notes that unplugging and reconnecting is a gentler first step than a factory reset, and the same is true for accessories, where a fresh battery and a soft reset fix most offline states without re-pairing anything.
Differential
Likely causes of “Hue accessories is offline or unavailable”, and how to tell them apart
- 1
A weak battery
What separates it The accessory drops out now and then because its battery has become weak
How to confirm Replace the battery with a fresh one of the right type and check the accessory reconnects
- 2
Out of range
What separates it The accessory shows offline in the app because it is out of range of the Bridge
How to confirm Move the accessory closer to the Bridge or add a mains powered light that can relay the signal
- 3
Zigbee interference
What separates it The accessory is intermittent because metal or other 2.4 GHz devices interfere with its radio link
How to confirm Move the accessory away from metal and from wifi equipment that can disturb the signal
- 4
An unhealthy Bridge
What separates it Every accessory is offline at once, which points to a problem with the Bridge itself
How to confirm Fix the Bridge first, by checking its lights and connection, before touching any accessory
- 5
A stuck accessory
What separates it The accessory does not respond at all even though the battery and range are fine
How to confirm Do a soft reset of the accessory, then pair it again in the Hue app if needed
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which lights on the Bridge are lit and which are off
- The age and the type of the battery in the accessory
- The distance to the Bridge and anything in between
- Which accessories drop out and which stay online
Try in this order
0 of 7 completedCheck the Bridge lights
ReversibleCheck the Bridge lights first, because accessories connect through the Bridge and a Bridge fault makes everything look offline.
Replace the battery
ReversibleReplace the battery with a fresh one of the right type, and check the polarity, since a weak battery is the commonest cause.
Check range
ReversibleCheck the range, which is about 30 feet from the Bridge, and less through thick walls and other obstacles.
Move away from metal
ReversibleMove the accessory away from metal and from other radio interference, and check whether it comes back online.
Soft reset the dimmer
ReversibleSoft reset the dimmer by holding all four buttons for about five seconds, which restarts it without removing it.
Re-pair in the app
ReversibleRe-pair the accessory in the Hue app if it stays offline after a reset, following the steps for its type.
Contact Hue
ReversibleContact Hue if it stays offline, and tell them the Bridge lights, the battery type and the distance.
Model-specific
What is true of this model and not of its siblings
- Motion sensor
- Uses two AAA batteries.
- Dimmer switch
- Uses a coin cell battery.
- Other models this page answers
- These steps also fit the Hue dimmer switch v2.
Stop boundary
When this stops being a self-service repair
- !If the accessory stays offline after a new battery and re-pair, contact Philips Hue support
- !If every accessory drops out at once, check the Bridge and its connection first
- !If only one drops, check range and battery
Evidence ledger
Sources behind this answer
Bridge lights and updates.
Soft reset and factory reset.
Motion sensor troubleshooting.
Battery type and life.
The company and its products.
Exact questions
Common questions
Why is my accessory offline?+
An accessory goes offline because of a weak battery, poor range or a problem with the Bridge itself.
Does a weak battery cause it?+
Yes, a weak battery is a very common cause, so replace it before trying anything more complicated.
How far can it be?+
Accessories work up to about 30 feet from the Bridge through walls, and less with obstacles in the way.
Can metal block it?+
Yes, metal can block or weaken the radio signal, so keep the accessory away from metal surfaces.
What is a soft reset?+
A soft reset means holding all four dimmer buttons for about five seconds, which restarts the switch.
Can a light relay signals?+
Yes, a mains powered Hue light can relay the signal, so a light placed between the accessory and the Bridge helps.
What batteries does the Hue motion sensor use?+
The Hue motion sensor uses two AAA batteries, which you fit behind the cover of the sensor.
How long do motion sensor batteries last?+
Motion sensor batteries last two to three years in normal use, depending on how often the sensor is triggered.
What does the dimmer switch use?+
The dimmer switch uses a coin cell battery, so check the type printed inside the battery compartment.
What is Zigbee?+
Zigbee is the low power radio protocol that Hue uses to connect lights and accessories to the Bridge.