This one comes up a lot and the answer is never in the product listing.

[getguardianeye]

ONVIF features are split across profiles, and a camera may support some profiles without supporting the rest. On product listings, “ONVIF” usually means live streaming through Profile S or the newer Profile T. That alone says nothing about recordings stored on the camera’s SD card.

Standard access to those recordings is covered by Profile G. A conformant Profile G device exposes recording, search and replay services. Many inexpensive cameras can record to a card without supporting Profile G, which leaves you dependent on the vendor’s app or a proprietary API.

Before buying, search the model in ONVIF’s Conformant Products database and check that the listed firmware matches the camera. If the model is absent, it is not officially ONVIF conformant, even if the manufacturer says that it uses ONVIF.

If you already have the camera, inspect the response to GetServices. Without the Recording, Search and Replay services, an ONVIF client cannot browse the card. The vendor’s software may still access it through a private protocol.

Profile G also gives an NVR the tools to recover recordings made at the edge. A camera can continue recording to its card during a network outage, and the NVR can later search for and retrieve that interval. Automatic detection of the gap, deduplication and stitching into the main archive depend on the NVR implementation. Profile G support alone does not guarantee that workflow.

For cameras without Profile G, FTP or FTPS upload can be a useful fallback when the model supports it. The camera decides which clips to upload and when to send them, while retry behaviour varies by vendor. It is less precise than an NVR requesting an exact missing interval, but it can still move recordings from the card into central storage.