How to factory reset a AVM FRITZ!Box router
Reset button location
No dedicated reset button — use #991*15901590* over a connected DECT phone, or the recovery image from AVM.
Hold duration
No physical reset button — uses a software / app procedure
What gets reset
Restores factory defaults including FRITZ!OS settings, Wi-Fi keys printed on the sticker, and admin password.
Brand-specific notes
AVM ships a unique per-device admin password printed on the underside sticker — there is no generic default. fritz.box is the mDNS name.