Home › Digital detectors vs test kits

Digital Radon Detectors vs Radon Test Kits: Which Should You Use?

Updated November 1, 2026 · General information, not medical advice

Some links on this page are affiliate links. If you buy through them we may earn a commission at no extra cost to you. How we make money.

The short answer: Both can help, for different jobs. A mail-in test kit is a low-cost, lab-analyzed way to test, and EPA's decision rules are built around kits and professional tests. A digital detector shows readings as they change and is best used for months, not days. A short reading on either one can mislead, so judge your radon level by a long-term average.

Not medical advice. This page repeats EPA and CDC guidance in plain words. Follow your state radon program and a certified radon professional for decisions about your home, and talk to a doctor about health concerns.

Side by side

	Mail-in test kit (passive)	Digital detector (electronic)
How it works	Charcoal, alpha track or similar device sits in the home, then goes to a lab. No power needed (EPA).	Electronic sensor shows readings on a display or phone app. Needs a battery or plug-in power (C-NRPP).
Results	A few days to a few weeks after you mail it (EPA).	Readings come quickly; C-NRPP says to wait at least 3 months for an average.
Short-term vs long-term	You pick: short-term (2 to 90 days) or long-term (over 90 days).	Models show short-term and long-term averages. Read the manufacturer's guide for how each is calculated (C-NRPP).
Price	Pennsylvania DEP: typically about $20 to $30 in that state.	We did not find a sourced price, so we do not quote one.
Home sale use	EPA's guide covers kit tests and professional tests.	C-NRPP says consumer monitors are not approved for use by radon measurement professionals.

Sources: EPA (Home Buyer's and Seller's Guide to Radon; A Citizen's Guide to Radon), C-NRPP 2024/25 consumer monitor report (a Canadian program), Pennsylvania DEP.

What to know before you buy a digital detector

Be patient. C-NRPP says radon varies from day to day and week to week. Short-term radon measurements can be misleading, either much lower or much higher than your actual average.
Run it for at least 3 months, preferably in the heating season (C-NRPP). If you have it for less than 91 days, C-NRPP recommends a long-term test as a follow-up.
Use the long-term average when deciding whether to fix your home (C-NRPP).
Check the brand. C-NRPP's report lists consumer monitors it tested and a separate list of devices it does not recommend, some recalled by Health Canada. C-NRPP is Canadian, so check your own state radon program for local guidance.
Units may differ. Canadian reports use Bq/m³. EPA lists 4 pCi/L as 150 Bq/m³. Our result checker accepts either.

A sensible plan

Start with a test that fits EPA's steps: a short-term kit or a qualified tester. See how to test correctly.
If the result is 4 pCi/L or higher, follow EPA's follow-up steps before spending money on a fix.
If you want to keep watching your level, a digital detector can show how it changes over time. Check your state radon program if you want to know how it treats consumer monitors.
After a radon system is installed, EPA recommends an independent test, and says it is a good idea to retest every two years.

Browse radon test kits Browse digital radon detectors

Common questions

Is a digital radon detector as good as a test kit?

It depends on the job. A mail-in kit is a low-cost way to get a lab-analyzed result. Canada's national proficiency program (C-NRPP) says consumer electronic monitors give results quickly but should be left in place at least 3 months to show your average, and that short-term readings can be misleading. EPA's decision steps are written around short-term and long-term tests, and the EPA pages we read do not tell homeowners how to use consumer digital monitors for those decisions.

How long should a digital radon monitor run?

C-NRPP recommends at least 3 months, preferably during the heating season when indoor radon levels are typically highest, and says to follow up with a long-term test if you only have a monitor for less than 91 days.

Where should I put a digital radon detector?

C-NRPP says to place it in a room that is occupied at least 4 hours each day. EPA's placement rules for test devices say to use the lowest lived-in level, away from drafts, high heat, high humidity and exterior walls, and at least 20 inches above the floor.

Can I use a digital detector in a home sale?

EPA's real estate guide describes qualified testers using continuous monitors with features to detect interference. C-NRPP says consumer monitors are not approved for use by radon measurement professionals. For a sale, EPA says to use a qualified tester or follow its checklist.

Related guides

Sources

Free printable: Radon Test Day Checklist

EPA's testing steps in one page, plus what your result means. Download the one-page PDF now, or get it by email along with a short series of five helpful emails.

Download the PDF