Does a WHOOP 4.0 band fit a WHOOP 5.0?

The short answer

No. A band built for WHOOP 4.0 will not mount on a WHOOP 5.0, and a WHOOP 5.0 band will not fit a 4.0. This is not about size or tension: the connector and the clasp changed shape between the two generations. No adapter closes the gap.

WHOOP 5.0 and WHOOP MG, on the other hand, share exactly the same connector. One band covers both devices, and that is true of every band we make.

How to tell which generation you have

The fastest route is the WHOOP app: open the device settings and the model name is written out in full. Ten seconds, no ambiguity.

Without the app, look at the device itself. The 5.0 and the MG are noticeably slimmer than the 4.0 and release from the strap with a tab. The 4.0 is thicker and slots into a different housing. If your WHOOP predates 2025, it is a 4.0 or older.

Why this is the number one reason for returns

Plenty of people buy a band by searching “WHOOP band” and never look at the generation. The photos look alike from one model to the next, the difference only shows at the connector, and it only becomes visible once the parcel is open.

It is by far the most common return we see, and it is entirely avoidable. Check your generation before you order, not after.

One exception worth knowing on WHOOP MG

If you own a WHOOP MG and you use the ECG or Heart Screener, note that both features need a conductive band. Woven bands, ours included, are not conductive. Every other reading — sleep, strain, recovery, heart rate — works exactly as before.

In practice most MG owners keep the original conductive band for ECG readings and wear a woven band the rest of the time. We cover this in our FAQ.

What to remember

• WHOOP 4.0 and WHOOP 5.0: incompatible connectors, both ways.
• WHOOP 5.0 and WHOOP MG: same connector, one band for both.
• ECG and Heart Screener on MG: a conductive band is required.
• Your generation is written in the WHOOP app, under device settings.

Our bands are built for WHOOP 5.0 and WHOOP MG only. Browse the plain colourways, the Already Late models, the printed models or the charms that clip onto the strap.

What fits a 5.0

Every band we make is cut for the WHOOP 5.0 and MG, not the 4.0: Pine, Lime and Fuchsia fit with no adapter.