The Dexcom G7 is not a small iteration on the G6 — it is a redesign of the whole system: hardware, wear experience and app. Here is every difference that actually matters if you are choosing between them or deciding whether to upgrade.
The quick answer
The G7 is 60% smaller, warms up in 30 minutes instead of 2 hours, adds a 12-hour grace period at the end of each session, is slightly more accurate, and can stream directly to Apple Watch. The main trade-off: G7 sensors are fully disposable (sensor + transmitter in one), so there is no reusable transmitter to keep.
Size and wear
The G6 uses a two-part design — a sensor patch plus a separate transmitter that clips in and gets reused for 3 months. The G7 combines both into one unit about the size of three stacked quarters. It is worn on the back of the upper arm (FDA-cleared placement) rather than the abdomen, and most users find it noticeably lower-profile under clothing.
Warmup: the biggest daily-life upgrade
Every sensor change on a G6 meant 2 hours without readings. The G7 warms up in about 30 minutes, and the 12-hour grace period means you can start a new sensor before the old one expires and switch over with zero data gap. Combined, these remove almost all CGM downtime.
Accuracy
Dexcom reports an overall MARD (mean absolute relative difference — lower is better) of roughly 8.2% for the G7 versus 9.0% for the G6. Both are approved for insulin-dosing decisions without confirmatory fingersticks. In practice, the difference is most noticeable in the first day of wear, where G7 tends to settle faster.
App differences
- Clarity built in: the G7 app shows time-in-range and GMI without opening the separate Clarity app.
- Redesigned home screen with event logging (meals, insulin, activity) on the main graph.
- Direct-to-watch: the G7 sensor itself can pair with a compatible Apple Watch — with G6, the watch only mirrors the phone.
- Share/Follow works the same on both: up to 10 followers.
Sensor supply and cost
Because G7 has no reusable transmitter, your prescription is sensors only — simpler refills, and replacement of a failed unit replaces everything. Pricing through insurance is typically similar to G6; see our cost and insurance guide for details.
Should you upgrade?
If your insurance covers both at the same tier, the G7 is the better system for almost everyone: faster warmup, smaller profile, no transmitter management and better accuracy. The main reasons to stay on G6 are pump compatibility (check that your insulin pump supports G7 — most major pumps now do) and existing transmitter stock you want to use up.
Ready to switch? Read our G7 app setup guide and check phone compatibility first.
Everything else you need — setup, compatibility and the free download — is on our Dexcom G7 app guide homepage.