Which local storage is best?

The four common storage designs

1. Built-in storage: simple, but fixed

Built-in eMMC memory is the easiest model to understand: storage is already inside the product. The Eufy Video Doorbell E340 includes 8 GB on the doorbell, so local event recording does not require a separate card or HomeBase.

The convenience has two limits. You cannot increase the built-in capacity, and an outdoor unit that is removed or damaged can take its locally stored footage with it. Whether that matters depends on your entryway, mounting security, and the availability of any optional off-device storage.

2. microSD in the doorbell: inexpensive flexibility

A removable card lets you select capacity and replace the storage if it fails. The Reolink Video Doorbell WiFi supports a microSD card up to 256 GB and can record motion events or continuous video. The card is not included.

Card endurance matters for continuous recording because the system repeatedly writes and overwrites video. Use a capacity and endurance rating appropriate for surveillance workloads, while staying within the manufacturer’s supported specifications.

3. Storage inside the chime: a useful middle ground

The Aqara Video Doorbell G4 places its microSD slot in the included indoor chime repeater rather than in the outdoor doorbell. Aqara supports cards up to 512 GB. Keeping the card indoors reduces the risk that someone removing the doorbell also removes the local recording.

This architecture still depends on the chime receiving power and maintaining its connection to the doorbell. Aqara also states that 24/7 recording requires the outdoor unit to be wired; battery operation and continuous recording are not interchangeable.

4. Hub or NVR: better separation and scale

A hub or network video recorder moves storage away from the entrance and can centralize recordings from multiple cameras. For a larger security system, that may be more important than minimizing the doorbell’s purchase price.

The tradeoffs are cost, space, power consumption, setup complexity, and ecosystem dependence. Verify that the exact doorbell, hardware revision, and recording mode support the chosen hub or NVR. Compatibility does not always mean every feature or recording mode remains available.

What happens when the internet goes down?

Local storage and internet independence are related, but they are not identical. A locally recording doorbell may continue detecting events and saving video during an internet outage, while remote live view, phone notifications, cloud backup, voice-assistant functions, and off-site access stop working.

Reolink documents that its wired WiFi doorbell can continue detection and microSD recording without internet, although mobile alerts and live view are unavailable. Do not assume every brand behaves identically; confirm offline behavior in the support documentation for the exact model.

How much storage do you need?

There is no honest universal conversion from gigabytes to days. Retention varies with resolution, compression, frame rate, clip length, motion frequency, audio, and whether recording is continuous or event-based. Manufacturer estimates are useful only when their assumptions resemble your entrance.

• Low-traffic, event recording: built-in memory may be sufficient.
• Busy entrance: expandable storage offers more margin.
• Continuous recording: prioritize high-endurance media and supported overwrite behavior.
• Multiple cameras: a hub or NVR can be easier to manage than separate cards.

Three examples from our shortlist