Choosing the right string matters just as much as choosing the right racket: it affects your power, control, spin, joint comfort and how long your stringbed lasts. But with hundreds of options on the market, how do you find your way?

Our X-Cord tool cross-references what you want from your game with X-Compare lab data measured on over 400 strings tested in-house. In 60 seconds, we'll offer you a tailored selection of tennis strings, matched to your racket, your level and your style. No more hesitation, no more strings chosen at random.

The X-Cord method: 5 lab axes + calculated tension

X-Cord doesn't just cross-reference two or three criteria. Our tool uses the 5 axes measured in the X-Compare lab for every string we list: power, control, spin, comfort, durability, plus material, gauge and, above all, compatibility with your specific racket.

Why measure strings in-house?

Manufacturer spec sheets often quote figures that are hard to verify. X-Compare is our independent testing programme: every string we list goes through the test rig to quantify its real-world properties, beyond the marketing. This database of over 400 strings feeds every X-Cord recommendation.

Ideal tension, an often-overlooked factor

Choosing a string isn't enough: the stringing tension radically changes how it behaves. The same string at 22kg or 26kg offers a completely different experience. X-Cord suggests the optimal tension for every recommended string based on your racket and your goals, a factor few tools take into account.

Racket and string: an inseparable pairing

A great racket, badly strung, plays badly. A great string on the wrong racket disappoints. That's why X-Cord takes your specific racket into account and flags potential incompatibilities (e.g. stiff polyester on a light racket = risk of joint pain). We look after your arm just as much as your feel.

Frequently asked questions

What string tension should you choose for your tennis racket?

The ideal tension depends on your racket, your string and your playing style. Generally, a low tension (22-24kg) gives more power and forgiveness, ideal for players looking for depth or those just starting out. A high tension (25-27kg) gives more control and precision, recommended for hard hitters or intermediate/advanced players. Our X-Cord tool suggests the optimal tension based on your profile and the string chosen.

Polyester or multifilament string: which should you choose?

Polyester is recommended if you're after control and spin, and you play regularly (heavy hitting, aggressive game). It's more durable but stiffer, not recommended if you suffer from tendinitis or arm pain.

Multifilament is recommended if you prioritise comfort, power, or have a sensitive arm. Softer and more forgiving, but it breaks faster and offers less spin.

If you're torn, a hybrid set-up (poly in the crosses, multi in the mains) is an excellent compromise.

Which string should you choose for more spin?

To maximise spin, head towards a textured or pentagonal polyester (Babolat RPM Blast, Luxilon ALU Power Spin, Solinco Tour Bite). The string's non-round shape grips the ball better on impact and generates more rotation. Paired with a slightly lower tension (-1kg versus your usual tension), you'll gain spin without sacrificing control.

How often should you restring your tennis racket?

A simple rule: restring your racket as many times a year as the hours you play per week. If you play 3 hours a week, restring 3 times a year even without breaking a string. If you play 6 hours a week, 6 times a year. After a few weeks, tension can drop by up to 20% and the string loses its properties, meaning you're playing worse without realising it. Competitive players often restring every 2-3 weeks.

Which string should you choose to protect your arm (tendinitis, tennis elbow)?

If you suffer from elbow or shoulder pain, go for a soft multifilament string (Tecnifibre X-One Biphase, Wilson NXT, Babolat Xcel) or even natural gut if your budget allows. These strings absorb vibrations and reduce shock transmission to the arm. Steer well clear of stiff polyester strung as a full mono set-up. Pair them with a moderate tension (23-25kg) to maximise comfort. Our X-Cord tool automatically identifies "arm-friendly" strings when you push the Comfort criterion.

Which string should you choose as a beginner?

For beginners, an entry-level multifilament or synthetic gut string is ideal: comfortable, forgiving and not too expensive (€10-15). It forgives mis-hits and protects the arm during the learning phase. Avoid polyester, which needs clean technique to be worth playing. Moderate tension of 23-25kg so you don't have to hit too hard.

What's the difference between a mono string set-up and a hybrid?

A mono set-up uses the same string in the mains (vertical) and the crosses (horizontal). This is the classic set-up. A hybrid set-up combines two different strings: typically polyester in the crosses (for control/spin) and multifilament or gut in the mains (for comfort/power). Hybrids let you fine-tune your feel and are widely used on the pro tour (Federer has played a gut/poly hybrid for years).