Best Ignition Testers of 2025

“I can't believe I never owned one of these before! I was troubleshooting a misfire on my 2-cylinder Kawasaki and didn't want to swap parts blindly, so I bought this tool. It's an amazing value for the money. Installation was a breeze; I connected it in line with the spark plug. After running the engine, I noticed a weak spark on one cylinder. I replaced the ignition coil, and now it's running great! A must-have for anyone who works on their own stuff.”

“These spark testers are incredibly handy! They’re made from durable hard plastic, and using them is straightforward. Just disconnect the coil and add the tester in-line. The bulb flashes brightly, making it easy to see, and the engine can still run with the spark plug installed. I’m really pleased with this product and would definitely choose this brand again if I need more!”

“I was excited to use the test light, especially since it arrived well-packaged. However, when I tried it, it wouldn't light up! Upon inspection, I found that the light bulb was cracked. This suggested poor quality control right from the factory. Returning it was a hassle because I had to drive a long distance to find a shipping location. Thankfully, Amazon eventually refunded me, but it was a frustrating experience.”

"I recently used the Ram-Pro InLine Spark Tester to diagnose ignition issues in my car and lawnmower, and I'm really impressed with its performance. This 6-12 Volt tester is reliable for both small and large engines. Its fool-proof design makes it easy to use for anyone, regardless of mechanical skills. It quickly checks for spark and the clear indicator helps determine if further investigation is needed. I love its versatility with different voltages and engine types. The solid build quality makes it feel durable and it's a handy tool for troubleshooting and maintenance. Overall, it's an excellent choice for anyone in need of a reliable spark tester!"

"I use this tester on small engines, like snow blowers and lawn mowers. It's great for letting me know if I have good spark. I find it easy to use; I just connect one end to the spark plug and the other to the spark plug wire."

"I found this product to have excellent build quality, it's safe and easy to use. The accuracy and brightness are great, although I wish the light was a bit brighter when using it outside. Overall, it works as expected!"

“I found it to be easy to use and the perfect size for my needs. It functions well, and the brightness is adequate for visibility. I would definitely buy it again.”

“This spark plug tester worked right out of the box for me. However, I did struggle to see the spark light during the day in my garage. I ended up closing the doors to see it better. The cable is a bit short, making it easier with two people. Still, it was very cheap and effective, so I’m giving it 4 stars.”

“My experience has been good so far. It’s straightforward to use, but I wish the bulb was brighter. It’s a little tough to see in daylight or bright environments.”

"As a solo mechanic, this tool has made my job significantly easier. I can easily confirm spark delivery without needing extra hands. Just attach it, crank the engine, and the spark is clearly visible!"

"I found this tool to be a great addition for troubleshooting small engines. The spark was strong enough to shock, although I wish it came with a better grounding option."

"This tester has worked exceptionally well for me. It's reassuring to know that if I see a spark, then my ignition is functioning properly. It's straightforward to use—just plug it in and clamp it to any ground."

"I find it very simple to use. I just place it over the coil pack while the engine is running, and the light flashes to indicate that the coil pack is good."

"I tried using this on my ignition coils, but it didn't detect anything at all. My car was running when I checked for misfires, and it didn't light up."

"This tool works great! It even comes with a magnet for testing its operation. I'm thinking about buying another one."

"These tools are great for diagnosing multiple plugs at once. I managed to pinpoint fuel issues effectively."

"They really helped me determine the problem with my dual-use coil packs. I couldn't be happier!"

"As a non-professional mechanic, I find this tool super easy to use. I tested it on a '96 Toyota with coil-on plugs, and it worked like a champ. Even if you can't see the spark, you can hear it clearly. It's a bit pricey, but as long as I'm careful with it, I expect it to last for many years."

"This tester is incredibly simple. I had trouble seeing the spark in bright sunlight, but shading it with cardboard did the trick. It's definitely worth the money for troubleshooting ignition and starting issues."

"I really appreciate this tester. It’s affordable and takes the guesswork out of whether there's spark. I did experience the spring mechanism coming apart on my first use, but putting it back together was straightforward. Overall, it helped me quickly diagnose a misfire."

"This product works well and has saved me a lot of time in troubleshooting."

"I had a misfire on my 2014 F150xlt 3.5L ecoboost. Using this tester, I found that all coils were good, and after replacing the plug, everything was back to normal. It's the easiest and most affordable tester I've used."

"I appreciate how easy it is to use and that it does exactly what it's intended for. It might feel a bit cheaply made, but it gets the job done!"

"I used this tool to test the spark plugs and ignition coils on my Subaru Forester. The spark gap allowed me to easily see a spark of about 3/4 inch, confirming that both the ignition coil and spark plug were functioning correctly. Given how tight engine compartments are these days, this tool definitely makes spark testing simpler."

"I appreciate this spark tester because of the adjustable spark gap. It really helps with various applications."

"I found this tool to be quite handy! It works well for testing sparks from a lawn mower to high GM systems. The instruction card is a valuable resource for voltages across different systems. It’s a good tool and a great value overall."

"I found it very effective for testing ignition coils and diagnosing issues. It's a great little product if you understand how it works."

"After installing the batteries, I returned to find it beeping uncontrollably on the table. I had to remove the batteries since it wouldn’t stop, which was quite frustrating!"

"I was able to test coil packs and injectors with ease. It helped me discover that my misfire was due to a simple hose issue, not the components I thought."