RadonIndex

Best Radon Testing and Measurement in Toronto & the GTA

Last updated: By RadonIndex Research Team

RadonIndex tracks 31 radon testing companies working across Toronto and the GTA, with a median 5.0★ Google rating across the 23 with three or more reviews. Installed radon testing typically runs $30–$60 per kit according to Homeowner.ca. RadonIndex ranks every company by the RadonIndex Score, built from what it states on its own website, its Google reviews and how complete its record is, never paid placement, so the shortlist below reflects the published formula.

Where do you need radon testing in the GTA?

Choose your neighbourhood or city to see the ranked shortlist and local pricing for that area. RadonIndex is expanding radon testing coverage across the GTA. More area rankings are published as enough local businesses are listed.

Which radon testing companies rank highest across the GTA?

All 31 radon testing companies in the Greater Toronto and Hamilton Area, ranked by the RadonIndex Score, which combines what each company states on its own website with its Google reviews and how complete its record is.

How much does radon testing cost in Toronto?

According to Homeowner.ca, long-term alpha track test kit, mail-in lab analysis runs $30–$60 per kit in the GTA, while evict Radon National Study at-cost kit runs $53.99–$53.99 per kit (Evict Radon National Study). Add 13% HST to any quote. The table below breaks down 3 line items, each with its own named source.

Typical GTA radon testing prices, August 2026. Each row cites its source.
ItemTypical rangeUnitSource
Long-term alpha track test kit, mail-in lab analysis$30–$60per kitHomeowner.ca
Evict Radon National Study at-cost kit$53.99–$53.99per kitEvict Radon National Study
Consumer continuous radon monitor$200–$350per deviceHomeowner.ca

See the full Radon Testing cost guide

How does RadonIndex rank radon testing companies?

Rankings can't be bought. RadonIndex gives each company one score out of 100: 40 for what it states on its own website, including a C-NRPP certification claim, 35 for its Google reviews weighted so a 5.0 on three does not outrank a 4.8 on three hundred, and 25 for how complete and reachable its record is. Across the GTA, 91% of the 23 radon testing companies with three or more reviews clear 4.8★, so ranking gaps are meaningful. Positions update as the score is re-run on new data. Read our full methodology.

Questions to ask your contractor

  • Is this a long-term test of three months or more, or a short screening test?
  • Which lab analyses the detector, and are they C-NRPP recognised?
  • Where exactly will the detector be placed, and is that the lowest lived-in level?
  • What does the written report include beyond a single number? What testing costs
  • If the result is above the guideline, do you also sell mitigation? Ask this before the test, not after.

Frequently asked questions

How much does radon testing cost in Toronto and the GTA?

According to Homeowner.ca, long-term alpha track test kit, mail-in lab analysis runs $30–$60 per kit, and evict Radon National Study at-cost kit runs $53.99–$53.99 per kit (Evict Radon National Study). Add 13% HST to any quote. RadonIndex's radon testing cost guide lists every line item with its source.

How do I choose a good radon testing company in the GTA?

Compare at least three written, itemized quotes rather than defaulting to the cheapest. RadonIndex ranks 31 radon testing companies at a median 5.0★ Google rating across the 23 with three or more reviews and a median of 33 reviews among those, so start with the shortlist above, then confirm insurance and recent local references before you sign.

When is the best time to arrange radon testing?

Start a long-term test in the heating season, roughly October through April, with windows in their normal winter pattern. That is when indoor radon runs highest and when the measurement guidance is written to apply. A test run through an open-window summer understates the level you actually live with.

Do I need a permit, and is HST included in radon testing quotes?

Add 13% HST: this work is taxable in Ontario and most published prices exclude it. A residential radon system does not normally need a building permit, but the fan is an electrical installation and the vent penetrates the roof, so ask who is pulling any electrical permit and who is responsible for the roof flashing. See RadonIndex's radon testing cost guide for what the published ranges include.

Can companies pay to rank higher on RadonIndex?

No. Rankings come from a published 0-100 score built from what a company states on its own website, its Google reviews and how complete its record is, never payment. Across the region, 91% of the 23 radon testing companies with three or more reviews clear 4.8★. Bear in mind a Google rating measures public reputation, not competence at radon work. Full details are on our methodology page.

What should you read next?

Compare RadonIndex's other Greater Toronto and Hamilton Area service rankings, or dig into the pricing and comparison guides for this project.