Fitbit does not use standard watch lugs. There is no 20mm or 22mm to measure, and no universal band that covers the range. Each product line uses its own connector, and in some cases generations within a line changed it too.
This guide lays out what shares with what.
First, identify your tracker
Turn the device over. Most Fitbits carry the model name printed on the back of the case, near the charging contacts. Use that, not the year you bought it, since Fitbit sold overlapping generations simultaneously and several look near-identical from the front.
The compatibility map
Charge 5 and Charge 6 share a band. One strap covers both. Charge 3 and Charge 4 share a band with each other, but not with the 5 or 6, which use a different and wider connector. Charge 2 shares with nothing.
Inspire 1, Inspire 2 and Inspire HR share a band with each other. Inspire 3 does not. This is the single most common mistake, because the names imply a continuity that does not exist in the hardware. Fitbit's own Inspire 3 documentation confirms the older bands are not compatible.
Versa 3, Versa 4, Sense and Sense 2 all share the same connector, so bands move freely between those four. Versa, Versa Lite and Versa 2 use an older pin-style band and form their own separate group.
Luxe uses its own connector and shares with nothing else in the range.
The pattern worth internalising: Fitbit changes band fittings at redesigns, not at version numbers. Two trackers released close together with different names often share a band, while two generations of the same name often do not.
How to order the right one here
Several of our bands are made for more than one tracker, and those listings carry a model selector alongside the colour choice. A band listed for the Inspire range, for example, lets you choose between Inspire 3 and the Inspire 2, 1 and HR group, and we ship the connector that matches. Pick your model there and the fit is handled.
Materials, briefly
Silicone is the default: sweat, showers, swimming, easy to clean, fine for sleep tracking.
Woven nylon and elastic are lighter and more breathable. Better for all-day and overnight wear, slower to dry after swimming.
Leather dresses the tracker up for work. Keep it out of water.
Stainless steel mesh gives the dressiest finish with a magnetic clasp that adjusts to an exact fit. Heavier, and not ideal for hard training.
Beaded and bracelet styles work particularly well on the smaller trackers, where the device can disappear into the design.
Changing a band
The mechanism is much the same across the range. Turn the tracker over, press the small flat button or lever where the band meets the case, and slide the band out. Line the new one up and press until it clicks.
Do both halves, then tug each gently. A half-seated band holds just long enough that you stop thinking about it.
Getting the fit right for heart-rate accuracy
The sensor reads best when the tracker sits snug against the skin, about a finger's width above the wrist bone. Many people wear theirs slightly higher during exercise and lower the rest of the time.
Too loose and the sensor picks up motion instead of pulse, which usually shows as a heart rate that lags behind effort or spikes at random. Too tight restricts blood flow and skews it the other way. A band you can adjust finely, like mesh or closely spaced silicone holes, makes this easier to get right than one with widely spaced notches.
