How to check a device yourself

This is the method we use, written out so you can apply it to something we have not covered — or use it to catch us being wrong. None of it requires special access. The first check does most of the work and takes about two minutes.

1. Look up the FCC grant

Anything sold in the United States containing a deliberate radio transmitter must hold an FCC equipment authorization, and the ID has to appear on the device or in its documentation. This is a legal requirement with an enforcement body behind it, which makes it far better evidence than anything a manufacturer writes in marketing copy.

Search fccid.io for the manufacturer and model. A grant for an intentional radiator lists the frequency bands, which tells you exactly which radios are inside — 2412–2462 MHz is Wi-Fi, 2402–2480 MHz is Bluetooth, 1920–1930 MHz is DECT, 902–928 MHz is a proprietary or Z-Wave-style link.

A Part 15B verification is the opposite of a radio grant — it covers unintentional emissions from ordinary electronics, and its presence supports the conclusion that there is no transmitter.

2. Do not trust an absent grant on its own

This is the step people skip, and it is the one that makes the check trustworthy. Finding no grant might mean the device has no radio — or it might mean you searched badly, or the grant is filed under a contract manufacturer's name.

Search the grantee, not just the model. Pull up everything that manufacturer has filed. If they demonstrably file grants for their models that do have radios, then the absence of one for your model is meaningful. If they have never filed anything, you have learned nothing.

This works because manufacturers routinely sell the connected and non-connected versions of the same product side by side. Their own paperwork for the connected sibling becomes the control that proves the quiet one is quiet.

Watch for the filing being under a name you do not recognise — Browning's trail cameras are filed by Quest Cameras, and Amana's commercial microwaves are made by ACP. A brand is not always a manufacturer.

3. Let a third party with enforcement power do the work

The FCC check works because someone who can punish a lie has already made the manufacturer answer the question. The same logic gives you other cheap, strong evidence:

• Standardised-exam approval. The SAT, ACT, AP and most professional licensing bodies prohibit devices capable of communication. An exam-approved calculator or watch has been certified radio-free by a body that enforces it.
• Commercial and food-service certifications (NSF, ETL-Sanitation) indicate equipment built for an operator who cannot tolerate cloud dependence — and those product lines document their controls precisely.
• Intrinsic-safety and hazardous-location ratings (ATEX, Class I Div 2) severely constrain what radios a device may legally contain.

4. Read the quick-start guide, not the box

Marketing copy says what the manufacturer wants to be true. The installation and quick-start guides say what setup actually requires, because they have to work. When the box says "no app required" and the setup guide opens with "download the app to begin", the guide is correct.

Specification tables are better still. Many manufacturers state connectivity as an explicit field — Wi-Fi: Not supported — which is about as unambiguous as evidence gets.

Manual aggregator sites tend to block automated access; go to the manufacturer's own support domain, or search for the specific procedure you care about, which usually surfaces their own knowledge-base article.

5. The model number is the whole story

Almost every trap in this subject is a model-number trap. Vendors sell the radio-free and radio-equipped versions under names a shelf tag will not distinguish: Brother HL-L2400D and HL-L2405W, Honeywell T4 Pro and T5, VIOFO A119 V3 and A139, Amana RCS10DSE and RCS10TS. A review of "the Brother laser printer" tells you nothing. Always resolve to the exact SKU before concluding anything.

6. Ask what happens when the router is off

Where a radio does exist, the question stops being can it connect and becomes what breaks when it doesn't. Work through these in order:

• Can setup be completed without creating an account?
• Does the device work with no network configured at all?
• Does it work with the WAN blocked but the LAN present?
• What specifically stops working — and is any of it the thing the device is for?
• Is there a documented local API, or a standard protocol like ONVIF, RTSP, Zigbee, Z-Wave or Matter?
• Can firmware updates be declined?

That last one matters more than the rest combined. A device that works offline today but accepts updates it cannot refuse works offline only until the manufacturer decides otherwise. It is also the question fewest manufacturers answer, which is itself informative.

7. Weigh what you found

We grade evidence in three classes and will not publish a tier on the weakest one alone:

One Class A source, or two independent Class B sources. Two sources are only independent if they are not quoting each other and not both derived from the vendor's own copy — five retailers repeating one spec sheet is one source, not five.

If you find we are wrong

support@dumbindex.com. We would rather be corrected than trusted, and this is what we commit to doing about it.