The Best Water Quality Test Kit for Your Home (2024)

I’ve been covering water-quality products for Wirecutter since 2015. In addition to conducting tests on pitcher filters, under-sink filters, and the Big Berkey countertop system, I’ve spoken extensively with filter engineers; with NSF, the de facto certification agency for water filters; and with the labs we’ve partnered with for our testing.

This guide is for anyone who’s worried about the safety of the drinking water in their home.

Such concerns are justified. The lead crises in Flint, Michigan, and Newark, New Jersey, an alarming national water study in Canada, and the 2023 discovery of forever chemicals (PFAS) in nearly half of US drinking-water sources have all called into question the safety of North American public water supplies, which had long been considered among the best and most tightly regulated on earth. (In 2001, the American Society of Civil Engineers named the US water supply one of the 10 “civil engineering achievements that had the greatest positive impact on life in the 20th century.”)

These crises have exposed some major vulnerabilities in our public water supply: aging infrastructure, imperfect public-safety practices, and a simple lack of knowledge about what’s actually in the water that flows from the nation’s faucets.

In the US, municipal water suppliers have to meet strict EPA limits some contaminants, including lead, mercury, pesticides, and industrial compounds. Every US municipal water supplier must share how well it measures up against the EPA standards in what’s known as a Consumer Confidence Report, or CCR, so checking your local CCR is a good first step toward knowing what might be in your water.

But water utilities are not required to test for every contaminant of concern, and as the Flint and Newark lead crises demonstrate, a CCR cannot account for problems that crop up downstream of testing stations. In both cities, changes to the water treatment regimen at the plant caused previously stabilized lead (in the form of old lead pipes and lead-rich solder) to dissolve, creating dangerously high levels of lead in the water that flowed from residents’ taps. A home test is the best and often only way to know exactly what is in the water that comes out of your faucet.

One last but important note: All of our recommended test kits are aimed at people who use public water supplies. (If you pay a water bill, that’s you.) The kits will work equally accurately for the roughly 43 million Americans who rely on well water—that is, they’ll tell you everything that’s in your water that they test for. But none of them test for radon, a groundwater concern in some regions. If you use well water, the EPA recommends getting a radon test; its Safe Drinking Water Hotline (1-800-426-4791) can advise you on qualified local labs. If you’re on a municipal supply but still concerned about radon, call or visit the website of your supplier and request a Consumer Confidence Report (CCR) to see if it's been tested.

Home water quality test kits come in two distinct types. First, there are true DIY kits, which have you dip a series of color-changing paper strips into a sample of your tap water and compare the results against a standardized color chart. Second, there are send-away kits, which have you take water samples and ship them to a lab for detailed, direct measurement of the contaminants.

They have very different price tags: Send-away kits cost anywhere from $100 to $500 or more, depending on how comprehensive an analysis you decide to get. DIY kits start at about $20 (for basic, lead-only testing) and run up to roughly $50 for a kit capable of detecting 20 or so potential contaminants.

Both will tell you if you’ve got lead in your water—the ability to do so was one of our criteria. But a top-of-the-line send-away kit can detect 100 or more metals, industrial compounds, and farm chemicals.

For DIY kits, we looked at those that are widely available online and in hardware stores and that list the contaminants they test for individually (rather than in generalities, such as “tests for metals and pesticides”). Lead had to be among them. We cast a wider net, ultimately buying six different kits.

For the send-away kits, we again did our usual research, looking widely at what’s available and at comments from people who’ve purchased them, as well as learning more about how labs are certified to conduct water quality testing. The labs that sell our send-away test kits are certified by the federal or state EPA to conduct compliance testing on public water supplies. Many labs have additional national and international governing-body accreditations, such as the National Environmental Laboratory Accreditation Program (NELAP) and the International Organization for Standardization (ISO). We wound up with a final group of five contenders.

To reasonably compare the various kits, we needed a control, so we worked with Pace Analytical—a national water testing firm, whose credentials appear here—to do extensive testing and give us an independent measure of what was in the tap water at my apartment in Queens, New York.

For the test itself, I followed the kits’ instructions as well as general best practices for water sampling, like leaving my kitchen faucet off for 12 hours prior to the collection. (That ensures an accurate “worst case” reading of, in particular, metals like copper and lead, which can leach from pipes and concentrate in the stagnant water overnight). I removed the faucet’s aerator in order to minimize the amount of gases trapped in the sample, which can affect the readings. Finally, for consistency, I used a water cooler to collect a single large sample (approximately three gallons) of my tap water and drew from it for all five kits and the control tests.

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 and later in a 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 tap water is very clean, I actually stopped using a water filter after I got my Tap Score results. After all, itt wasn’t really doing anything, since there wasn’t much of anything to do something about. When I retested the Advanced City kit in my hundred-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.

If for some reason you can’t find or use Tap Score, we recommend the WaterCheck CityCheck Deluxe or the Safe Home Ultimate water testing kits. They, too, cover a broad range of potential contaminants, including lead, mercury, arsenic, and other metals; trihalomethanes; bacteria; and farm chemicals. And they are each analyzed by nationally certified labs, meaning you can use them no matter where you live in the US. (CityCheck is sold and analyzed by National Testing Laboratories, and Safe Home Ultimate by Environmental Laboratories.)

The big drawback with both of these kits is that their reports lack the clear explanations that set Tap Score apart. Instead, they simply color-code the results. That lets you quickly scan your results for any problem areas, but it doesn’t help you understand what the results mean and what you can do to address any concerns.

Both kits are more expensive than Tap Score, as well. And you have to pay to ship the CityCheck Deluxe kit to the lab. To be clear, part of their higher cost is that both kits test for a somewhat wider range of contaminants than Tap Score. The WaterCheck CityCheck Deluxe gives readings for 114 contaminants, versus Tap Score’s 108, and the Safe Home Ultimate gives readings for 149. But the additional readings are largely minor variants of compounds that Tap Score already tests for and that are themselves uncommon to begin with, so we don’t think this outweighs Tap Score’s superior report.

The Tap Score PFAS Water Test specifically looks for 14 different so-called forever chemicals, or PFAS, which are of increasing concern in the US water supply. It delivers the same ease of use, clear and actionable reports, and responsive customer service that make the Tap Score Advanced City Test our top pick. (The Advanced City test does not look for PFAS. And this test does not check for the chlorine, metals, and volatile organic compounds that the Advanced City test does.)

PFAS (per- and polyfluoroalkyl substances) are used in the manufacture of many common household goods, including nonstick cookware, water-resistant clothing, and stain-resistant upholstery. That means there are multiple well-documented sources of potential exposure. Such exposure has been linked with a host of health risks, including cancer, obesity, and weakened immune function.

Because PFAS do not break down over time, they can also accumulate in the environment and end up in drinking-water supplies. As a result, people and animals who use that water will be exposed to PFAS daily. Nearly half of US tap water—both from public utilities and from private wells—contains PFAS, according to a 2023 US Geological Survey study.

When I checked the water in my New Jersey home with the Tap Score PFAS test, it flagged two results with alerts. My PFOS measured 0.00387 parts per billion, and my PFOA measured 0.0061 parts per billion. In April 2024 the EPA set the enforcement limit for both compounds in drinking water at 4 parts per trillion, so my water effectively measured at or just above that level (3.87 and 6.1 ppt, respectively). One other PFAS, perfluorononanoic acid (PFNA), came in at 2.35 ppt—the EPA limit is 10 ppt—and the rest were below detectable limits. I’m comforted to know my water is not a major PFAS source, and I’m glad that I don’t have to pursue any remediation before I can enjoy a drink straight from the tap. (Full disclosure: I initially miscalculated, or more accurately, completely borked the math. I thought I was over the EPA limit by a factor of 1,000, and was planning to install a whole-home or undersink PFAS filter.)

Truth be told, every DIY test kit we looked at contained the exact same lead-test materials; the Safe Home Do-It-Yourself kit is our budget pick because it’s widely available at hardware stores and comes from a long-established lab. To do the test, you place a small sample of tap water into a test tube and then insert a clearly marked paper strip. Ten minutes later you simply check whether your test strip shows a blue line, indicating the presence of lead above the federal limit of 15 parts per billion. (Yes, it reminded us of home pregnancy tests, too.)

We think DIY lead-test kits are genuinely useful. They’re inexpensive, virtually foolproof, and quickly tell you whether you’ve got lead in your water—the most common concern people have about their plumbing. If you do get a positive result, you can then take further steps, like getting a full lab test or calling in a water-treatment specialist. If you get a negative result, you’ve given yourself peace of mind for about $20.

Though we think DIY lead tests are worthwhile, we didn’t like the more comprehensive (and more expensive) DIY kits that we tested, and we recommend against using any of them.

It’s not that they’re difficult to use. It’s that they’re almost impossible to read.

First of all, most of the readings are subjective: You have to try to match, by eye, the color of the various test strips to the printed charts that come with the kits. It’s rarely a black-and-white, positive-or-negative distinction; you’re instead judging your results against a subtle range of a single color. And outside conditions (like the quality of light in the room, or color blindness) can make the task even harder. I repeatedly found myself questioning my own eyes.

Second, the tests are rushed. A typical test strip might need to be swirled in water for 20 seconds, shaken off, and then read against the chart within another 30 seconds. That’s because the test reading (the color the test strip turned) continues to change after the strip is removed from the sample. Mess anything up, or get stuck on trying to decide which color best matches your results, and you’ve lost your chance of an accurate reading. And all of this is made much harder when, as is the case with some kits, you have multiple different tests on a single strip. (One such kit, the Med Lab 16 in 1, asks you to judge 16 different readings simultaneously.)

I tested six different DIY kits, taking (or, more precisely, attempting to judge) close to a hundred measurements. And when I finished, I was less confident that I knew what was in my water than I had been at the beginning.

A couple more points against the DIY kits: They don’t give you the actual contaminant levels in your tap water; all you get (if you trust your eyes) is a rough estimate of their concentration. And finally, even the best DIY kits are not very comprehensive. The most thorough one we found covers just 20 potential contaminants; send-away kits can detect and directly measure 100 or more, across a wider range of contaminant classes.

Again, we think DIY lead-test kits are an excellent value, and if lead is your only worry, they are a quick and inexpensive way to tell whether you have a problem. But if you want a broader analysis of what’s in your water, we strongly believe send-away lab tests provide value worth paying for.

Send-away kits

Drinking Water Specialists’ Bang-for-the-Buck was the least-expensive send-away kit we tested, but despite that, it measured a wider range of contaminants than many such kits, including our top-pick Tap Score. But many of those contaminants are of little practical concern (they’re either rare, or minor variants of more common contaminants whose general presence would stand for all). More important, this kit’s report was barely readable: just a black-and-white spreadsheet of names, test results, and incompletely explained EPA standards. Also, while we were writing this guide, this kit became unavailable on Amazon, and the direct-purchase link (above) is hard to navigate.

The Test Assured Home Inspection Water Test Kit advertises that its “tests can detect lead and heavy arsenic, chlorine, fluoride, radon, bacteria, and hundreds of other contaminants.” In reality, it delivered measurements of only six: arsenic, coliform bacteria, E. coli itself, lead, nitrate, and nitrite. That extremely limited range of contaminants, plus the high cost for so few measurements and the very basic report—which offers no analysis or advice—made this kit an easy dismissal.

DIY kits