The Best Water Quality Test Kit for Your Home

Top pick

This send-away kit delivers lab-tested measurements of more than 100 contaminants, and it explains what they mean and what to do if there’s a problem.

The Tap Score Advanced City Water Test is our pick among all the test kits—both DIY and send-away—we looked at. It covers a range of 105 different contaminants, including lead, mercury, arsenic, and other metals; trihalomethanes (a wide class of industrial chemicals); pesticides; bacteria; and nitrates (from farm runoff). After using it twice—once at my apartment in Queens, New York, and later in my century-old home in New Jersey—I’m convinced it’s the most convenient, user-friendly way for homeowners to know for certain what’s in their tap water.

On the critical point of accuracy, Tap Score—and all the other send-away kits we tried—performed exceptionally well, closely mirroring the results we got from our control sample. But it completely outshone all of the rest in the way the results were reported.

Some send-away kits return a virtually indecipherable spreadsheet that simply lists which contaminants were detected and the EPA-designated maximum contaminant level (MCL), leaving you to try to make sense of what your results mean. Others do a bit better, color-coding the spreadsheet to make it easier to see where your readings indicate a potential problem. But Tap Score highlights areas of concern right up top, and it explains in plain language what your readings mean and what steps you might take to address anything problematic (for example, installing an under-sink filter or using a filter pitcher).

Take a look at three reports, from Tap Score, CityCheck, and Bang-for-the-Buck:

The differences are plain. Tap Score’s report gives you your actual readings, an explanation of what each individual reading means, and why it matters. CityCheck color-codes and uses symbols to indicate whether your readings are below or above federal guidelines or recommendations—which is helpful when you’re scanning the spreadsheet for things you might be concerned about, but not for interpreting those concerns. Bang-for-the-Buck just lists your sample’s readings and the EPA’s limits in a black-and-white chart. It’s barely readable and almost completely uninterpretable.

Tap Score also pulls out any readings of special concern and puts them front and center. My water in Queens, for example, registered an elevated (but nonetheless very low: 0.00353 parts per million) level of bromodichloromethane:

That result accorded with the results from our other send-away test kits and our independent control test. But only Tap Score highlighted this result (instead of leaving me to find it in a spreadsheet). And only Tap Score offered any explanation of what bromodichloromethane is (a byproduct of disinfectants and of municipal water treatments); described its health risks (developmental defects, kidney and liver damage, nervous system problems); told me what level is considered risky (0.1 ppm, or 28 times my tap water’s level); and suggested how I might remove it from my tap water (use an activated carbon or reverse-osmosis filter).

Tap Score also showed slightly elevated levels of chloroform, copper, and iron in my water. The readings were all similar; none of them exceeded federal limits; and the latter two were readily explained: My apartment building was constructed in 1964, and its iron and copper pipes have begun to corrode.

The readings on all the contaminants tested for, which in most cases showed “none detected,” were also similar to the control sample. That adds to our confidence that Tap Score is accurate.

Given the evidence that my Queens, New York, tap water is very clean, I actually stopped using a water filter after I got my Tap Score results. After all, it wasn’t really doing anything, since there wasn’t much of anything for it to do something about. When I retested the Advanced City kit in my 100-year-old New Jersey home in 2024, it again revealed slightly elevated levels of a few substances, but nothing that prompted me to take action. Put another way, the test gave me a lot of peace of mind about the quality of the water coming out of those aging pipes—so I see no need to fuss about with a filter.

In addition to Tap Score’s accurate test results and useful analysis of them, we also admire its overall ease of use. Registering our tests was simple thanks to Tap Score’s clean, modern website. The instructions for how to take your samples, included with the kit, are well written and sensibly organized. And Tap Score includes a mailing label and box and utilizes multiple carriers (USPS by default; UPS and FedEx by request), which means you’re likely to be near a convenient drop-off. None of our competitors matched all—or, in some cases, any—of these helpful features.

A final feature that set Tap Score apart from the competition was its customer support. When you get your report (it’s sent as a Web page, downloadable as a PDF), there’s a live chat function that you can use to ask questions about your report directly. If the chat moderator can’t answer it—for example, if you have a technical question about treatment options or want to know details about a specific contaminant—your question is forwarded to one of SimpleLab’s staff experts (they include a licensed professional engineer and a team of academic experts who specialize in water-quality issues). One of them will email you an answer within a day or two.

Flaws but not dealbreakers

As a general rule with these kits, you’re buying directly from the manufacturer. That makes the transaction a little bit cumbersome. There is an option to order Tap Score on Amazon, but to get your report, you have to affirm to Amazon that it can share your email with Tap Score. According to a company representative, about 15 percent of Amazon buyers either miss or ignore the confirmation request, meaning they cannot get their test results.