String Tension AI vs Tension Lab

Measure tennis string tension. Make your next restring count. String Tension AI is an iPhone app for measuring tennis string tension, tracking tension loss and choosing when to restring. Tap your racquet's stringbed near the microphone to get a tension estimate in kg or lb. No external hardware needed. AVAILABLE IN 8 LANGUAGES English, German, French, Italian, Spanish, Brazilian Portuguese, Simplified Chinese and Danish. The app follows your iPhone's language, with regional dates, numbers and currency. Choose a different app language in iOS Settings. MEASURE AND TRACK FOR FREE • Take unlimited measurements for one racquet and review your 20 most recent readings. • Get live quality coaching, cross-checks across multiple taps and calibration against a known reference tension. Readings that do not hold up are set aside from guidance. • Follow How to Measure with narration and captions in all eight languages. • Check String Health, tension trends and restring guidance based on usable readings. • Track full beds, hybrids, custom strings and separate main/cross tensions. CONNECT YOUR PLAYING AND STRING HISTORY • Log session duration, intensity and racquet; review the calendar, set goals, build streaks and celebrate milestones. • Review and import tennis workouts from Apple Health for free, with possible duplicates flagged. Optional heart-rate access can suggest intensity without saving heart-rate data. • Open My Stringers from the Strings hub to manage contacts, favorites, archives and restring history for free. • Browse expanded racquet and string catalogs and ATP, WTA and Legends setups. Save favorite strings, add ratings and discover daily tennis facts. • Share visual cards for supported string-health, tension, string-job and achievement highlights. GO FURTHER WITH PRO • Unlimited racquets and string setups, full measurement history and Measurement Insights. • Advanced tension-decay analytics; compare racquets, strings and completed string jobs. • Personalized string and hybrid recommendations using your playstyle, ratings and eligible retention history. • Tension Advisor with What If scenarios for your equipment, game and conditions. • Tension targets, optional alerts and Smart Detection for likely fresh strings or unusual tension changes. • Playing-hours restring forecasts when enough dependable data is available. • Automatic Apple Health import, detailed playing stats, advanced milestone tools and reminders. • Cost Analytics, cost per playing hour, annual budgets, wishlist and stringer Annual Summary with PDF export. • iCloud sync and PDF/CSV reports, including string-job reports for your stringer. ASK STRING AI COACH Ask about your racquet, tension, strings, playing history, restring timing and costs using your saved data. Questions, answers and racquet data stay on device. Available when the app is set to English, on compatible Apple Intelligence devices with iOS 26 or later, a supported system language and an available on-device model. Some questions require PRO. READY WHEN YOU ARE Check String Status widgets on your Home or Lock Screen. Use Siri, Shortcuts, Spotlight or the Action button to reach supported actions. Import, inspect and restore backups. Measurement audio is processed on device and never saved or uploaded; imported Health session records stay on your iPhone, outside iCloud sync and session exports. Shared summaries may include their totals. Optional analytics require consent. Enjoy smoother measuring, browsing and sharing, more reliable history, forecasts, reports and sync, plus VoiceOver, Dynamic Type and Reduce Motion support. Requires iOS 17 or later. Download free. Learn from every session. Restring with confidence. Terms of Use: https://stringtensionai.com/terms/ Privacy Policy: https://stringtensionai.com/privacy/

Your strings change every time you play. Tennis Tension Lab helps you see that change before it surprises you on court. Place your phone beside the racquet and tap the center of the string bed three to five times. The app analyzes the sound on your device and gives you a repeatable tension estimate in seconds. KEEP YOUR SETUP CLEAR • Check current string tension • Compare each reading with the baseline from a fresh string job • Follow tension loss on a simple timeline • See when it may be time to restring • Keep every racquet, string job, hybrid setup and note together • Find models quickly in a catalog of 1,347 racquets and 216 strings • Compare string characteristics before choosing your next setup MADE FOR THE COURT No account is required to start. Tap audio is analyzed in memory and discarded; only measurement results are saved. Choose lb or kg and keep your history organized by racquet. For the most consistent results, measure the same racquet in a quiet place with the same tapping method. Readings are estimates based on sound and equipment information, not certified measurements from a stringing machine.