Qlipp Sensor Review – Huge Potential but is it Accurate?

We were so excited to road test the first tennis sensor that obtains its data from the string bed. The Qlipp Sensor has been developed with Crowd Support by an outfit in Singapore known as 9 Degrees Freedom. They claim the Qlipp is the lightest sensor available on the market. It would want to be given its location and the possible effects on racket performance.

Device Usability 6/10

The Qlipp Sensor doesn’t come with the excess baggage of the Sony Smart Sensor, nor the special mounts and chargers of the Zepp. Just a sensor and a generic charger that plugs directly into the device. We like it already!

Getting it on and off the racket was…….well…….tricky. It’s not as simple as turn and click as suggested by the developers. In fact, it can be downright difficult. The Qlipp boys are suggesting the fix for this will be a charger with an L-shaped chord allowing the user to charge the device while it’s in the racquet. Not a great solution as this means the extra weight of the Qlipp Sensor (8g) remains permanently in your racket head. Not something you want.

Moving on from the attachment and we find the Qlipp Sensor connects easily via Bluetooth to our Android and iOS devices. A nice lady even tells us when we’re connected and disconnected (a great advantage considering the other devices are not so audible when they disconnect). Just tap the screen and start hitting balls.

One thing that needs to be noted is that the Qlipp Sensor doesn’t have any data storage like Zepp and Sony SS. The device must be connected to your mobile or tablet rather than having the option of downloading session data later. This is kind of a bummer but not a deal breaker.

Qlipp Sensor Scorecard

Qlipp Tennis Sensor. Data and Analytics from the String Bed of Any Racket

  • On-Court: Attachment is difficult + need your Phone/Tablet - Score: 6/10
  • Data Accuracy: Not Great. Misses some of the basics - Score: 3/10
  • App: Clunky, too much info and display is confusing - Score: 5/10
  • Video: Standout of the device/app - Score: 7/10
  • Overall: Has Problems that need addressing. Potential is there - Score: 4/10

Data 3/10

Ball speed and spin data from the Qlipp Sensor iOS app

Sorry folks. This one’s a bit of a let down. The Qlipp developers receive major points for trying to display shot by shot analytics of our hit sessions. The trouble was we couldn’t get a session where the accuracy of groundstroke identification (whether a forehand or backhand was played) above 85% and sometimes significantly lower than that. We tried with different players, different rackets and different balls to no avail.

85% accuracy may not sound too bad. But when you consider how that skews data, both in a session and over time, it’s not nearly high enough. And 85% is top of the range for this product in our court testing.

We’re also not a fan of the 3 spin types used by Zepp, Qlipp and Bab Play. It’s so very rare for a ball to be hit with NO spin ie flat. For more info on this topic, see our article here.

As for the rest of the data, the ball speeds were wildly different from that of Sony (yes, we tested with both sensors in the racket at the same time), although we’re unsure at this stage as to the accuracy of either.

The Sweet Spot data is a little confusing as it doesn’t provide the player with information about where on the string bed the ball was struck. Just a number between 1 and 100 measuring how far from the middle it was struck. That’s problematic as players and coaches want to know where they missed if they didn’t hit the sweet spot, as there could be an inherent problem with a player’s swing.

App 5/10

Qlipp Sensor App home screen. It's slick and professional but once inside, it feels clunky

It looks really cool and sleek when you first open it up but once inside it feels a bit clunky. It’s almost as if the developers have tried to add “unnecessaries” in order to better the competition, rather than focus in on the important stuff.

It’s also pretty obvious that the Qlipp Sensor developers have copied a lot of their App functionality and displays from the Babolat Play App.

Let’s also remember that the App can only be as good as the data provided to it, and on this level, the Qlipp has problems as noted above.

Within the App, the Overall Stats for a session shows a score out of 100 for three parameters: Speed, Spin and Sweetspot and then provides an average score out of 100. It’s not something that’s in any way useful and is also confusing because spin and speed have an inverse relationship when hitting a tennis ball ie the more you have of one the less you have of the other, so how can they be part of the same score?

In the Breakdown and the Skills sections we find values for “Stroke Heaviness” and “Depth”. The former is related to the amount of spin out of 100 and the amount of power out of 100. We’re not sure what the “Depth” measurement is. Both measurements are examples of the developers coming up with a number that they understand but is totally alien to a tennis player. We’d prefer to see them stick to more basic information like racket head speed. According to the Qlipp Sensor website, the device measures racket head speed but it’s not something that the App displays. Why? We’re not sure.

Video 7/10

Qlipp Sensor App video. One of the saviours of the app, the video function allows for the different slo mo speedsThe video section of the app is the standout. It misses next to the Sony SS because you can only drill down to view forehands and backhands whereas the Sony allows you to view slice backhands separately to topspin backhands for example.

What we did like was the fact that Qlipp lists all shots for the video session rather than bringing them up one by one a la Sony SS. Also unlike Sony you can view the video in portrait or landscape.

Further, the slow motion is infinitely better than the Sony SS. The Sony’s slo mo is frame by frame and so doesn’t give the full shot analysis. The Qlipp on the other hand, has the ability to slow video down to 1/2, 1/4 or 1/8 speed and it’s continuous slo mo rather than frame by frame.

Overall 4/10


Potential, and lots of it. The video function of the app is good, as is the ability to use the device inside the string bed. The flexibility to use this with all rackets and all string (well, almost) is what’s most exciting.


Data accuracy. Qlipp is not your social media tennis tool. It’s trying to compete with Sony Smart Sensor as a tool with useful analytics so the basics have to be right. At this stage, they’re not. The app needs more work to trim down the fat of unwanted and unneeded information. It’s clunky and unspectacular in the aesthetics department.

Final Word on The Qlipp Sensor

We’ve tried so very hard to give the Qlipp Tennis Sensor a better than pass mark. The fact is, we can’t recommend it as an analytical tool for tennis players until certain glitches are solved. Somewhere around 80% success in reading groundstrokes and serves just doesn’t cut the mustard. The potential is there, however, for this device to be extremely good with some more refinements.

We hope the developers haven’t released it to market too early as this version feels like a beta rather than the finished product. There’s potential here, but if they’re trying to compete with the analytics calibre of the Sony SS, the developers will need to do more.

2 Replies to "Qlipp Sensor Review - Huge Potential but is it Accurate?"

  • Sergey
    January 14, 2018 (5:31 pm)

    Qlipp is a very bad sensor. The developers are extremely reluctant to contact in case of defective product. I have more than a month can not get a clear answer. My sensor loses the connection after each hard shot (e.g. – first serve). And it’s not a Bluetooth problem, it is a problem of the sensor. The quality of his workmanship. On my claim there is no clear answer from the developer. Requirements the replacement, repair or refund are ignored. In addition, a sensor (when it is working, i.e., for slow shots) recognize shots very bad. For example, the serve takes over a forehand. It is very bad works as a vibration damper. It very much changes the feeling of the racket and the ball. I do not advise to buy it..

    • Nick
      January 15, 2018 (4:40 am)

      It’s disappointing that a product with potential looks like it’s fading from existence. Late last year (2017) the developers were fire-saling the Qlipp sensor for as low as 49USD. Unless there’s a major upgrade in the offing, we don’t see it returning for another batch.

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