My AirTag doesn't show up on iPhone and appears dead

If it’s not playing a sound when you insert and press down on a fresh battery, that’s typically the first indicator that the device isn’t powering up at all.

As such, see if any of the following can help:

• Make sure you're using a CR2032 battery — the standard coin-cell type AirTags use. Also, double-check that it’s not one with a bitter coating, as those can interfere with contact points. Positive (+) side should face up when inserted into the AirTag.
• After placing the battery in, press down firmly and hold until you hear a sound. This chime should confirm it's getting power. If no sound plays, try gently rotating the battery while pressing down, in case the contacts are slightly misaligned or oxidized.
• Sometimes the contacts inside can get dirty or slightly corroded — especially if the device was exposed to moisture. You can try using a dry cotton swab or soft cloth to clean the inside. Avoid metal tools to prevent shorting anything.
• Just to rule out a dud battery, try another one from a different package or brand.

If you've tried all this and it's still unresponsive (no sound, no connection), the AirTag is likely faulty.