DJI Osmo Action 4: the published specs, and the one number that is genuinely low

The published specifications

Everything below comes from DJI's own Osmo Action 4 specification page, read on the date in our sources. Where DJI does not publish a figure, the row says so rather than filling it in from a review or a retailer listing.

18 meters is the whole reason to care

Bare waterproof depth is the first specification we weight on any action camera, at 30% of the score, and the reason is simple: a camera that clears your depth without a housing has better audio, no sealed-air fogging risk, nothing extra to flood, and no second product to buy. A camera that does not clear it turns into a two-product purchase.

At 18m, this camera clears essentially every recreational water activity that is not scuba. Snorkeling happens in the top few meters. Swimming and paddling happen at the surface. A capsize puts the camera a meter down, briefly. Even a confident free-dive on one breath rarely passes 10m. Against that, 18m is not a specification you are using up — it is margin, and margin is the correct place for a depth rating to sit, because a rating describes a new camera with clean seals in still water and makes no promise about a three-season-old door or the pressure spike of a wave. The full version of that argument is on how deep an action camera can actually go.

For comparison, on published figures: GoPro rates the HERO13 Black to 33ft (10m) bare, Insta360 rates the Ace Pro 2 to 39ft (12m), and DJI rates the current Osmo Action 5 Pro to 20m. This camera, superseded and cheaper, sits second in that list. If the water rating is the specification that brought you here, this is the most depth per dollar on the site — it is why it appears on the snorkeling picks and why the deep-water route runs through the scuba page.

The cold rating nobody reads

DJI publishes an operating range of -20°C to 45°C (-4°F to 113°F). Most manufacturers publish nothing at all here — GoPro gives no operating temperature range on either of its current flagship pages — so the fact that DJI states one is itself worth something.

It matters for this site's buyer specifically. Shoulder-season paddling means cold hands and colder water; a winter ride means a camera that has to wake up at freezing. Cold is where batteries quietly lose a third of their published runtime, and a camera with no stated low-temperature limit is a camera you are guessing about. Plan for less than 160 minutes when it is near freezing regardless — that is physics — but plan with a number rather than a hope. The arithmetic for a cold day out is on action camera battery life compared.

Stabilization: named, versioned and still current

DJI lists RockSteady 3.0, RockSteady 3.0+, HorizonBalancing and HorizonSteady on this camera. That is a full stabilization suite with version numbers, which is the thing budget cameras cannot match — and stabilization is the criterion we weight second-heaviest, at 25%, because a kayak deck slaps and a rooty descent buzzes in ways a handheld walk test never shows.

HorizonSteady is the one worth understanding. It locks the horizon level through camera rotation, which is what you want on a mount that rolls: a handlebar through a berm, a paddle shaft, a chest mount as you lean. HorizonBalancing is the lighter-touch version that corrects tilt without the full lock and without the same crop. The practical difference between the three stabilization systems in this category is explained on HyperSmooth vs FlowState vs RockSteady.

The 10MP catch

Here is the specification that does not appear in the marketing. DJI publishes a maximum photo resolution of 3648×2736 and describes single-shot stills as approximately 10MP.

In a category where GoPro publishes 27MP and budget cameras advertise 48MP, 10MP is genuinely low. It is enough for a phone screen, a social post or a web image, and it is not enough if you intend to crop hard or print. If you were planning to use this as a stills camera on a trip — the one camera you take, shooting both video and photos — that is the reason to think again.

What it does not affect is video, which is 4K up to 120fps on a 1/1.3-inch sensor and is the entire point of the camera. The honest framing is that this is a video camera with a stills mode attached, not a hybrid. If stills matter as much as video to you, the comparison you actually want is action camera vs mirrorless, which is a different question from which action camera to buy.

What you give up against the current model

DJI replaced this camera with the Osmo Action 5 Pro, and the gap is narrower than a generation usually is. The sensor is the same 1/1.3-inch size class. The low-temperature rating is the same -20°C. The bare depth went from 18m to 20m, which is a rounding difference at depths neither camera will see.

The two real differences: published runtime, 160 minutes against 240, and the front screen. The Action 5 Pro's front OLED is genuinely more useful for framing yourself than the Action 4's front display, and if you film yourself talking to camera it is worth money. If you mostly mount the camera and point it away from you, it is worth nothing. We put the two side by side on Osmo Action 5 Pro vs Osmo Action 4.

The other thing you give up is time. A superseded camera gets less firmware attention, accessories taper off, and stock narrows as it sells through — so prices move around and availability is worth checking before you plan a trip around it. That is the standing trade on any previous-generation body, and it is the same caveat we put on GoPro HERO13 Black vs HERO12 Black.

Who should buy it

Buy it if water is the point: snorkeling, swimming, kayaking, paddleboarding, anything where the bare depth rating is the specification that decides. Buy it if you shoot in the cold and want a published operating range rather than a guess. Buy it if you want flagship-class stabilization and a 1/1.3-inch sensor at a superseded-model price, and you can live with the shorter published runtime.

Skip it if you need stills as well as video, if you film yourself talking to camera and want the better front screen, or if you want the camera to be current for the next five years. Skip it too if you are already inside the GoPro mount ecosystem and do not want to re-buy adapters — the mount question is the one that catches people after the purchase, and it is covered on action camera mount compatibility.

Where it sits against everything else is on the best action cameras, and the three-brand version of the decision is GoPro vs Insta360 vs DJI.

How we scored it

We do not own a test lab and we have never claimed to. The score on this page is an editorial judgment built from published manufacturer specifications, weighted for lake-and-trail use: water survival 30%, stabilization in chop 25%, battery in the cold 20%, mount ecosystem 15%, footage you will keep 10%. This camera scores as highly as it does because it is strong on the three heaviest criteria and the weighting does not reward megapixels — which is also why the 10MP stills figure costs it less here than it would on a general-purpose camera site. The method is on our editorial policy.