Do WHOOP 4.0 bands fit WHOOP 5.0? Check your model before buying a band, and how 4.0, 5.0 and MG differ

Upgraded from WHOOP 4.0 and your old band won't go on? It isn't broken: WHOOP changed the device size and clasp for 5.0 and MG. See which bands work across models, how to read your device ID, and which device comes with One, Peak and Life.

8 October 2026Updated 1 November 20266 min read

In short

WHOOP 4.0 bands don't fit 5.0 or MG, and 5.0 or MG bands don't fit 4.0, because the device size and clasp changed.
5.0 bands fit an MG device, but it can't take an ECG on them, because ECG needs an MG band.
Check the device ID on the side of the sensor or in the app: it starts with 4, 5 or MG.
Chargers don't cross over either: after upgrading, neither your 4.0 bands nor its charger will work with the new device.

You open the box on a new WHOOP 5.0, reach for your favourite 4.0 band, and it won't go on. You haven't put it on upside down and the band isn't faulty: WHOOP made the new device smaller and redesigned the clasp, so bands from the two generations were never meant to swap.

Can 4.0 and 5.0 bands be swapped?

Not in either direction. WHOOP's help pages say 4.0 accessories aren't compatible with 5.0 or MG devices, and the 4.0 Fast Link slider won't take the new bands or clasps either.

The reason is size: 5.0 and MG are about 7% smaller than 4.0, so the clasp size and the way the band mounts to the device changed with them, and the Fast Link slider was redesigned too.

Chargers work the same way. The 4.0 Battery Pack won't charge a 5.0 or MG; the new devices use their own Wireless PowerPack or USB-C Basic Charger.

Which band fits which device

Band	WHOOP 4.0	WHOOP 5.0	WHOOP MG
WHOOP 4.0 bands	Fits	Doesn't fit	Doesn't fit
WHOOP 5.0 bands	Doesn't fit	Fits	Fits, but no ECG
WHOOP MG bands	Doesn't fit	Not stated by WHOOP	Fits, with ECG
LUXE MORE SuperKnit Luxe	Doesn't fit	Fits	Doesn't fit
LUXE MORE SportFlex	Doesn't fit	Fits	Fits, with ECG contacts

The table summarises WHOOP's help pages, which we checked on 8 October 2026. We have found no WHOOP statement on MG bands on a 5.0, and a 5.0 has no ECG hardware in any case.

How to tell which WHOOP you have

The surest way is the device ID printed on the side of the sensor. In the app, open More, go to your account settings, choose Device Settings and tap Advanced. The ID starts with 4, 5 or MG, depending on the model.

If the ID isn't handy, these clues help:

Battery: a 4.0 lasts about 5 days per charge; 5.0 and MG about 14 days.
Charger: a 4.0 uses the 4.0 Battery Pack; 5.0 and MG use the Wireless PowerPack or the USB-C Basic Charger.
Size: 5.0 and MG are about 7% smaller than 4.0, which shows if you put two side by side.
MG: a matte black body with brushed metal details, and it comes with a WHOOP Life membership.

Don't guess the model from the membership alone. WHOOP's help pages say that outside the US, Canada, Mexico, Europe and the UK, One may come with a certified pre-owned 4.0, even though WHOOP Thailand's membership page lists One with a 5.0. Whenever you're unsure, check the device ID before ordering a band.

How 4.0, 5.0 and MG differ

WHOOP launched 5.0 and MG together on 8 May 2025. Compared with 4.0, both are about 7% smaller, battery life goes from about 5 days to about 14, the heart-rate and skin-temperature sensors improved, and the band and charging systems are all new.

MG stands for Medical Grade. It looks almost identical to 5.0 but can take an ECG when paired with an MG band and a Life membership. The three memberships come with these devices and bands in the box:

Membership	Device	Band in the box	Price per year in Thailand
One	WHOOP 5.0	CoreKnit in Jet Black	฿6,999
Peak	WHOOP 5.0	SuperKnit	฿8,549
Life	WHOOP MG	SuperKnit Luxe	฿12,999

Prices and box contents are taken from WHOOP Thailand's membership page on 8 October 2026 and may change.

Features differ by tier too: Peak adds Health Monitor, Stress Monitor and Healthspan to One, and Life adds Blood Pressure Insights and Heart Screener (ECG) on top of Peak.

Upgraded from 4.0: what to do with the old bands

If you still use the 4.0, keep the bands for it, or pass them on to someone who still wears one. The new device needs a new set of bands, since there is only one in the box.

Three old knit straps tied with string in a kraft box, beside a Coffee SuperKnit Luxe band with a gold clasp on tissue paper — Put the old bands away or pass them on, and start a new set for the new device

If you used to swap bands by the day on your 4.0, start with two: a neutral you can wear every day, and one for work or for days you dress up. Once you know how you like to swap, add colours later.

Using an MG: can you wear other bands?

Yes. WHOOP says MG fits 5.0 bands, and sleep, Recovery and Strain still track as usual. The one thing you lose is ECG, which needs an MG band whose clasp has indents and a conductive coating for your fingers to touch during a reading.

ECG is only available in some countries. When we checked WHOOP Thailand's membership page on 8 October 2026, ECG was still marked as not available in this region. If it launches in Thailand, keep one MG band for the days you want an ECG and swap in others the rest of the time.

Which models LUXE MORE bands fit

Our bands are third-party accessories with compatibility that varies by family: SuperKnit Luxe fits WHOOP 5.0 only, while SportFlex fits WHOOP 5.0 and WHOOP MG and includes ECG contacts. Neither family fits WHOOP 4.0.

Not sure which model you have? Send us a photo of the side of the sensor on LINE @890tunir and we'll check before you order.

Shop SuperKnit Luxe for WHOOP 5.0

Shop SportFlex for WHOOP 5.0 and MG

How to choose a band colour

Frequently asked questions

Do WHOOP 4.0 bands fit WHOOP 5.0?

No. WHOOP says 4.0 accessories aren't compatible with 5.0 or MG, because the new devices are smaller and use a new clasp.

Do WHOOP 5.0 bands fit WHOOP 4.0?

No. The 4.0 Fast Link slider can't take 5.0 or MG bands and clasps.

Do WHOOP 5.0 bands fit WHOOP MG?

Yes. Sleep, Recovery and Strain track as usual, but you can't take an ECG, which needs an MG band with a conductive clasp.

Does the WHOOP 4.0 charger work with 5.0?

No. The 4.0 Battery Pack won't charge a 5.0 or MG; use the new Wireless PowerPack or Basic Charger.

Do One, Peak and Life use the same bands?

According to WHOOP Thailand's membership page, One and Peak come with a 5.0 and Life with an MG, so 5.0 bands fit the devices of all three, though an MG can't take an ECG on them. If your device turns out to be a 4.0, it needs 4.0 bands.

Do LUXE MORE bands fit WHOOP 4.0?

No. Neither our SuperKnit Luxe nor SportFlex bands fit WHOOP 4.0. SuperKnit Luxe fits WHOOP 5.0 only; SportFlex fits WHOOP 5.0 and MG and includes ECG contacts.

Compare every WHOOP band

Wear WHOOP for accurate data

LUXE MORE is an independent store selling third-party accessories and is not affiliated with, endorsed, sponsored or authorised by WHOOP. WHOOP, WHOOP 4.0, WHOOP 5.0, WHOOP MG and the band names mentioned are trademarks of WHOOP, Inc. WHOOP details in this article were checked against WHOOP's help and membership pages on 8 October 2026.