Samsung Galaxy Fit 4 leak reveals Bluetooth upgrade but leaves GPS unanswered

Samsung’s Galaxy Fit 4 has cleared the FCC, confirming model SM-R391 and giving us the first proper look at Samsung’s next fitness band. Dig a little deeper into the test documents and there is more here than the already reported Bluetooth 5.4 upgrade, including details about the hardware revision, software build, battery supplier and charging setup.

There is little doubt over the identity of SM-R391. Samsung’s own FCC documentation repeatedly uses the name “FIT4”, while the current Galaxy Fit3 carries model number SM-R390. The filing received final FCC approval on August 4.

That takes the Galaxy Fit 4 beyond the rumour stage. Samsung has working hardware going through regulatory testing, and some of the documents give us a surprisingly detailed snapshot of what was sitting on the test bench in July.

The test unit looks fairly far along

An interesting detail comes from the EMC report. Samsung submitted hardware marked REV2.0 running software version R391XXU0AZG2. The test lab received the sample on July 15 and carried out its EMC testing on July 20, while Bluetooth testing followed on July 22 and 23.

That does not tell us Samsung has finished the retail hardware, but REV2.0 is at least consistent with a device that has moved beyond an initial engineering prototype. The timing also fits with earlier reports suggesting Samsung could launch the band in the coming months.

The new FCC drawing suggests Samsung is not tearing up the Fit3 design. The back again has a central optical sensor area, two charging contacts and release mechanisms for the straps. There is also a physical button along the edge. From what we can see, this looks much more like an evolution of the Fit3 than another big design shift.

That is probably sensible. The Fit3 already moved the range much closer to smartwatch territory with its large 1.6-inch AMOLED display and aluminium body. Its basic hardware still holds up reasonably well against inexpensive fitness bands from Xiaomi, Huawei and others.

Samsung is testing four charging bases

The deeper test reports also reveal something that has not received much attention elsewhere. The Fit 4 sample uses an EVE battery carrying model number HQ-8339EV. Unfortunately, there is no capacity listed, so we cannot yet tell whether Samsung has increased the 208mAh battery used in the Fit3.

Samsung also supplied four different charging bases for certification testing. They come from Shenzhen Pomagtor Precision Electronics, Huizhou Juwei Electronics, Saibao Jiangxi Industrial and Huizhou Washin Electronics. The report says every charging base was tested, although only the worst-case result was recorded.

That probably does not point to four different chargers being sold with the band. A more likely explanation is that Samsung has qualified several suppliers to manufacture the same accessory. Still, it gives us a little more evidence that the Fit 4 supply chain is already taking shape.

For comparison, the current Galaxy Fit3 has a 208mAh battery rated for up to 13 days. Battery capacity is therefore one of the specifications worth watching when more Fit 4 documentation appears.

Bluetooth 5.4 is confirmed but GPS is not settled

The main wireless upgrade is straightforward. Samsung’s SAR report lists Bluetooth 5.4 with BR/EDR and Bluetooth Low Energy support across the 2.4GHz band. The Fit3 uses Bluetooth 5.3.

There is no FCC evidence of Wi-Fi, NFC, LTE or UWB. All of the transmitting radios covered by the filing operate between 2402 and 2480MHz, so Samsung appears to be keeping the Fit 4 on the simpler side of its wearable range.

GPS is a different story. Some coverage of the filing has stated that the Galaxy Fit 4 does not have built-in GPS, but the FCC documents do not actually establish that. The absence of a GNSS transmitter listing is not enough to rule it out because satellite positioning is receive-only.

That leaves GPS as one of the biggest unanswered questions. The Fit3 relies on a connected phone for positioning, while some rival fitness bands now offer standalone satellite tracking. Adding it would make Fit 4 much more of an upgrad

More details are being kept under wraps

There is plenty Samsung is not ready to show yet. The external photos, internal photos, test setup images, quick-start guide and full user manual have all been granted short-term confidentiality. The FCC database currently lists January 31, 2027 as their public availability date. Samsung’s confidentiality request specifies a 180-day period from the equipment authorization grant.

That date should not be taken as a release date. Manufacturers regularly request the maximum confidentiality window and can have the material released sooner when a product launches.

For now, the FCC filing gives us a useful halfway point. The Galaxy Fit 4 is real, Samsung has REV2.0 hardware under test, Bluetooth 5.4 is confirmed and production components such as the EVE battery and several charging-base suppliers have already been documented. What we still do not know is arguably more interesting, particularly battery capacity, standalone GPS, sensor upgrades and whether Samsung plans to keep the Fit3’s aggressive pricing.