Everything New With Apple Watch Series 6

The Apple Watch Series 6 launched at Apple's September 2020 event, the first one held entirely virtually due to the pandemic. The major new feature is a SpO2 sensor that measures blood oxygen saturation in about 15 seconds. The other changes (a faster chip, always-on altimeter, new colors, the SE as a cheaper companion model) are individually smaller but collectively make the Series 6 the most meaningful Apple Watch update since the Series 4 redesign.

The Blood Oxygen Sensor

The headline feature. The Series 6 has a redesigned set of LEDs and photodiodes on the back of the watch that can measure blood oxygen saturation (SpO2) by shining red and infrared light through the wrist tissue and measuring how much of each color is absorbed. The reading takes 15 seconds and gives you a percentage from 70% to 100%.

Apple has been careful to position this as a wellness feature, not a medical one. The watch isn't FDA-cleared for medical-grade SpO2 measurement, the way it is for ECG. The reading is meant to be informational, useful for tracking trends rather than diagnosing anything specific.

The pandemic context is unavoidable: SpO2 is one of the early indicators of respiratory issues from COVID-19, and Apple's launch in September 2020 happened while a lot of people were thinking about whether their oxygen levels were normal. The feature is genuinely useful in that context, but the medical-grade caveat matters: a SpO2 reading from a wrist-mounted sensor is meaningfully less accurate than from a finger pulse oximeter, particularly for people with darker skin tones, where the wrist sensors have known accuracy issues.

The S6 Chip and Always-On Altimeter

The S6 chip is roughly 20% faster than the S5. In practice, the watch feels snappier in app launches and complications, but most users won't feel a substantial difference. The always-on altimeter is the more meaningful background feature: instead of triggering only during a workout, the altimeter is now sampled continuously, which means the elevation tracking on hikes and stair climbs is more accurate, and the workout app can report elevation changes correctly without needing to be manually started.

The Display

The always-on display from Series 5 is still here, but it's noticeably brighter when the watch is in the "ambient" (wrist-down) state. Series 5's always-on mode dimmed so aggressively that you couldn't read the time in direct sunlight without raising your wrist. Series 6 fixes that. Indoors and in shadow, the dim mode is still meaningfully more battery-friendly than full brightness; outdoors, it's actually readable.

New Colors and Bands

The Series 6 adds a blue aluminum case and a (PRODUCT)RED aluminum case. The blue is a deep navy, slightly muted, that pairs well with several of the new band options. The red is brighter than the iPhone 12 (PRODUCT)RED, more like a fire-engine red.

The Solo Loop and Braided Solo Loop are the new band designs. They're stretchy, one-piece bands with no clasp or buckle, which makes them faster to put on and visually cleaner. The catch is sizing: each band is sized to a specific wrist measurement, and Apple's printable measurement guide is the only way to figure out which size to order. Returns of mis-sized Solo Loops have been reportedly high.

The Apple Watch SE

The bigger strategic move at the same event was the Apple Watch SE, a $279 watch (versus $399 for the Series 6) that has the Series 5's hardware: same screen size, same case, same chip, no always-on display, no ECG, no SpO2. The SE is positioned as the iPhone XR equivalent in the Watch lineup: most of the value, none of the premium-tier features, much lower price.

For most buyers, the SE is the right answer. The Series 6's headline features (SpO2, ECG) are nice-to-have rather than daily-use. The everyday Apple Watch experience is identical between the two. The Series 6 is for buyers who specifically want the health-monitoring features or the new always-on improvements.

Should You Upgrade?

From a Series 5: probably not. The improvements are real but small, and a year-old Series 5 still gets watchOS updates and the always-on display. From a Series 4: maybe, especially if the SpO2 feature appeals to you. From a Series 3 or older: yes, the cumulative improvements are large and the SE alone is a meaningful upgrade.

The Series 6 is the kind of mid-cycle update that Apple has gotten very good at. Each individual change is incremental. The cumulative direction (more health monitoring, faster chip, better always-on display, lower price tiers) is exactly where the Apple Watch needs to be going to stay ahead of Wear OS and Fitbit. The 2021 successor (Series 7) and beyond are where the next big architectural moves are likely. The 6 holds the line, and the SE expands the audience meaningfully.