★★★★★
"Finally an app that lets me check if my stringer actually hit the tension I asked for. Measured right after stringing and again a week later — really useful data."
Free Android App
Strike your strings — RacketTension detects the vibration frequency and calculates exact tension in real time. No hardware. No guesswork. Just your phone.
100%
Free to download
20+
String types supported
4.5★
Google Play rating
0
Hardware needed
Step by step
No expensive hardware required. RacketTension uses your phone's microphone to analyse vibration frequency and convert it to accurate tension data.
Enter your racket surface area, stringing pattern, and string type. The app remembers your settings for future measurements.
Remove your vibration dampener, tap Record, then strike your strings with your fingernail or another racket. The mic picks up the vibration.
The app calculates string tension instantly in kg or lbs. Track your measurements over time to monitor string ageing.
See it in action
See exactly how to use RacketTension to get accurate string tension readings on your Android device.
What you get
FFT-based frequency analysis gives you accurate tension readings within seconds. No expensive tension meters needed.
Uses your phone's built-in microphone. Works on most Android devices without any accessories.
Log measurements after each session to understand how your strings lose tension and when to restring.
Built-in database of popular strings including Luxilon Alu Power, Babolat RPM Blast, Head Hawk and more.
Switch between kilograms and pounds in settings. Compatible with all string tension standards worldwide.
Download and use the core measurement features for free. Save money on professional tension meters.
What players say
"Finally an app that lets me check if my stringer actually hit the tension I asked for. Measured right after stringing and again a week later — really useful data."
"Simple to use, accurate results. I compared it against a professional tension meter and it was within 1kg. Impressive for a free app."
"Great concept, works well in a quiet room. I now measure my rackets every month to know exactly when to restring. Saves money in the long run."
Got questions?
No. RacketTension uses your Android phone's built-in microphone to detect string vibration frequencies. No external sensors, cables, or accessories are needed. Just your phone.
The app uses FFT (Fast Fourier Transform) analysis of string vibration frequency to calculate tension. In a quiet environment, results are typically within 1–2 kg of a professional tension meter. Best results are obtained by removing your vibration dampener before measuring.
This is completely normal. String tension drops 20–30% immediately after stringing due to stress relaxation. The important thing is not the absolute value, but comparing your tension over time to understand string ageing and decide when to restring.
RacketTension is compatible with most Android smartphones running Android 6.0 or higher. The app requires microphone access permission to function.
Yes. RacketTension is free to download on the Google Play Store. Core measurement features are available at no cost. A subscription is available for unlimited measurements and advanced history tracking.
Ready to start?
Free download. No hardware. No guesswork. Join thousands of players who already use RacketTension.