Review: DJI O4 Air Unit Pro – What You Need to Know Before Buying

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The DJI O4 Air Unit Pro is one of the most exciting FPV product releases of 2025. This camera and video transmitter combo is capable of transmitting and recording HD video that rivals high-end action cameras. By eliminating the need for a separate action camera, the O4 Air Unit Pro reduces weight, lowers cost, and simplifies your FPV drone setup. Here’s an in-depth look at what sets the O4 Pro apart, where it could improve, and how it stacks up against the DJI O3.

Ready to install and set up the DJI O4 Air Unit Pro in your FPV drone? Check out my complete setup guide here: [xxx guide coming soon… stay tuned].

Two Versions

DJI released the O4 Air Unit in two versions, each catering to different FPV drone needs:

1. DJI O4 Air Unit (aka O4 Lite): Compact and budget-friendly, weighing under 10 grams.
2. DJI O4 Air Unit Pro (aka O4 Pro): A high-end option packed with advanced features.

This review focuses on the O4 Pro. For details on the O4 Lite, check out my dedicated review: [xxx will be published on a later date].

Where to Buy

You can purchase the DJI O4 Air Unit Pro from the following retailers:

Design, Size, and Weight

The O4 Air Unit Pro introduces several design improvements over the O3, including the new heatsink fins to enhance cooling performance.

They’ve returned to the dual antenna design – both antennas are LHCP (left hand circularly polarized).

The O4’s camera is significantly larger than the O3’s, allowing for a larger image sensor.

Despite being slightly larger in overall dimensions than the O3 (32.6 x 30.7 x 14.1mm vs. O4 Pro’s 33.4 x 33.1 x 13.1mm), the O4 Pro is notably lighter—about 7 grams less than the O3.

Here’s the dimensions of the O4 Air Unit Pro:

• Air Unit Dimensions: 33.4 x 33.1 x 13.1 mm
• Camera Dimensions: 25 x 23 x 20 mm
• Antenna Length: 50mm wire + 54mm (3.5mm OD plastic tube)
• Camera Wire Length: 130 mm
• Flight Controller Cable: 100 mm
• Weight: 32.5g

O4 vs. O3: Key Differences

Is the O4 better than the O3? Absolutely. The O4 outshines the O3 in nearly every aspect.

Here’s a quick comparison of the key features:

Image Quality

The DJI O4 Pro’s camera receives a significant upgrade over DJI O3, now featuring a larger 1/1.3-inch sensor that enhances low-light performance and overall image quality.

[xxx place holder for side-by-side comparison to the O3]

One of the standout improvements is the O4 Pro’s dynamic range and shadow detail. It captures far more information in darker areas, making it superior to the O3, Walksnail Moonlight, and even my GoPro Hero 11 in both daylight and low-light scenarios. The larger sensor enables the O4 Pro to gather more light, resulting in improved clarity and a broader range of brightness levels, especially in challenging lighting conditions.

For FPV pilots, the live feed you see in the goggles is impressive. The O4 Pro streams 1080p video at 60Mbps to the DJI Goggles N3 and Goggles 3 (and 1080p at 50Mbps to Goggles 2 and Integra). This matches the DJI Avata 2 in terms of performance.

Onboard Recording

Here’s a sample footage of the Avata 2 which uses the same camera:

The O4 Air Unit Pro supports 4K recording at up to 120fps and offers D-Log M, ideal for color grading in post editing. D-Log M results in a flat, neutral-looking video feed, but DJI offers an in-goggle mode that enhances color and contrast of the live view for pilots without affecting the recorded footage. Very nice.

With a recording bitrate of 130Mbps, slightly lower than the O3’s 150Mbps, the difference is negligible for most users, as platforms like YouTube compress videos anyway to much lower bitrate.

The O4 Pro includes 4GB of onboard memory, much less than the O3’s 20GB. However, this can be a lifesaver when you forget your SD cards, ensuring you won’t go home empty handed. For expanded storage, the unit supports microSD cards up to 512GB.

Range and Penetration

In FCC mode, the DJI O4 Air Unit Pro’s output power can reach up to 1200mW on the 5.8GHz band, whereas in CE mode, the maximum is only 25mW. However, DJI has introduced the ability to use the 5.2GHz band at up to 100mW for CE users, but this only works in Auto mode. If you manually select 100mW in manual mode, the power will still default to 25mW on 5.8GHz.

DJI claims the Max Transmission Range with goggles 3 and N3 is 15km (FCC) or 8km (CE). However, I suspect it will exceed that. DJI’s FPV systems are known to have a hard range limit, which is related to software constraints rather than hardware. The exact hard limit for the DJI 04 Air Unit is currently unknown. For reference, the DJI Avata (V1) using the O3 system is advertised at max 10km range, but has a real-world hard range cap of 23km. Further testing is needed to confirm this.

With Goggles 3, you can now select a 60MHz bandwidth (60Mbps bitrate), while Goggles 2 is limited to 40MHz (50Mbps bitrate). Wider bandwidth generally offers better range, penetration, and image quality when flying alone. However, in my testing, the performance difference between 40MHz and 60MHz is there, but not like night and day. If you’re flying with others, a wider bandwidth can cause more interference. To minimize this, consider using a lower bandwidth or, better yet, Race Mode.

Power Level Options

The O4 Air Unit allows manual power adjustments, unlike the O3, which automatically manages power levels. The power level options are: Auto, 25mW, 50mW, 100mW, 200mW, 400mW, 700mW, and 1200mW.

• FCC Mode: More channels are available, and up to 1200mW output power.
• CE Mode: Limited to 25mW on the 5.8GHz band. However, in Auto mode, it can switch to the 5.2GHz band and use 100mW.

FCC Unlock

You can unlock FCC mode on the O4 Air Unit using the same ham file hack as the O3. This unlock provides additional channels and full power levels, provided you are flying in a country where FCC operation is legal.

I will provide step-by-step instructions for enabling this feature in my upcoming setup guide. Stay tuned! [xxx link to tutorial]

Racing Mode

The new Racing Mode promises to reduce latency to as low as 15ms on the O4 Pro and 20ms on the O4 Lite when used with Goggles 3 (G3) and N3. This could be a game-changer for FPV racers, or those after the lowest possible latency. Additional advantages include the use of standard Race Band channels and cleaner transmission, making it ideal for flying in groups with reduced interference.

Note that Racing Mode is only available with Goggles 3 and N3 and is not supported on Goggles 2 or Integra.

[xxx place folder for image quality comparison]

Latency

The advertised lowest latency for the O4 Pro is as follows:

From my experience, the latency is comparable to, if not better than, the O3 system and is totally flyable for freestyle. Note that these latency figures apply to Racing Mode; in Normal Mode, latency is expected to be higher.

While changing resolution has no apparent effect on latency, frame rate does. 100fps provides the lowest latency, but it is only available in 1080p. The ranking of frame rates by latency is:

• 100fps (lowest latency, 1080p only)
• 50fps (second lowest latency, available at all resolutions)
• 60fps and 120fps
• 30fps (highest latency)

For N3 goggles, the ideal frame rate is 50fps. While you can select 100fps, the N3 display only supports up to 60Hz, meaning the frame rate will be halved (to 50fps) in the goggles, resulting in slightly higher latency compared to 60fps.

Mounting in FPV Drone Frame

On the VTX side, the DJI O4 Air Unit is largely similar to the O3, so most frames designed for the O3 should also work with the O4. The O4 offers additional mounting flexibility with 20x20mm mounting on one side and 25.5×25.5mm mounting on both sides. This is an upgrade over the O3, which only supported 25.5×25.5mm. The O4 also uses all M2 screw holes instead of the smaller M1.6, making it more robust and user-friendly.

The real challenge lies in fitting the camera in the frame. The O4 camera is significantly larger than the O3 camera, even though both have a 20mm width. The O4’s increased length and “unique” screw hole spacing mean that most frames designed for the O3 won’t accommodate the O4 camera. For some frames, custom-designed 3D-printed mounts may be required, but if you’re purchasing a new frame for the O4, make sure it’s compatible to avoid surprises.

The O4 camera features two M2 screw holes with a 16mm spacing between them, a strange mounting pattern that is unlikely to work with existing frames.

Pro Tip: When mounting the O4 Pro, use spacers under the Air Unit to ensure the USB-C port is accessible, as it sits right on the edge and could be blocked without proper spacing.

Pinout and Connection

The pinout and wiring for the O4 Air Unit are identical to the O3 (VCC, GND, RX, TX, GND, SBUS), and the input power requirements remain the same. If you’re upgrading from the O3, you can unplug the O3 and plug in the O4 directly without modifying your flight controller wiring.

Additionally, the O4 includes solder pads for direct soldering, a welcome improvement for custom builds that adds flexibility for non-standard setups.

Camera Compatibility

The cameras in the O4 Pro, O4 Lite, and O3 are not interchangeable. The coaxial cables for the O4 and O3 cameras are not compatible. While the O4 Pro and O4 Lite use the same MIPI connector, connecting the O4 Lite camera to the O4 Pro Air Unit (or vice versa) does not work.

Goggles Compatibility

The O4 Pro and O4 Lite Air Units are compatible with the DJI Goggles 3, Goggles N3, Goggles 2, and Goggles Integra. However, there are key differences in functionality across the goggles:

• Goggles 3 and N3: Support all the features of the O4 Air Units, although the N3’s display is limited to 60Hz.
• Goggles 2 and Integra: Limited to a maximum bitrate of 50Mbps and do not support Race Mode.

Despite the O4 transmitting only 50Mbps to the Goggles 2, it performs admirably, offering image quality and range comparable to the Goggles 3 with 60Mbps transmission. This makes the Goggles 2 a more versatile choice, as they are compatible with the DJI O3 as well as older systems like the Vista and FPV Air Unit.

Remote Compatibility

The O4 Pro has a built-in radio control link, allowing it to be used with DJI’s remotes without requiring a third-party radio receiver. The compatible remotes are:

• RC2: Works with Goggles 2 and Integra only.
• RC3: Works with Goggles 3 and N3 only.

While DJI’s remotes are convenient, I personally recommend radios from brands like Radiomaster or Jumper, paired with ExpressLRS. These offer superior control precision, better ergonomics, advanced features and performance.

Heating Performance

So far, I haven’t encountered any overheating issues with the O4 Pro, likely because of the cold winter temperatures where I live (5–10°C). The improved heatsink design should provide adequate thermal performance in warmer climates, but further testing in hot weather will be needed to confirm this.

Specifications

Here’s the full specs of the DJI O4 Air Unit Pro:

• FPV Live Feed:
  • 1080p 30/48/50/60/100fps
  • 60Mbps on Goggles 3 and N3, 50Mbps on Goggles 2 and Integra
• Lowest Latency:
  • DJI Goggles 3 in Racing Mode: 15ms
  • DJI Goggles N3 in Racing Mode: 19ms
  • DJI Goggles 2 or Goggles Integra: 30ms
• Onboard Recording: Up to 4K 60FPS at 130Mbps, supports D-Log M
• Storage: Built-in 4GB + MicroSD Card Slot (up to 512 GB)
• OSD Support: Betaflight & iNav
• Antenna: Dual Antenna
• Built-in Stabilization: RockSteady 3.0
• Camera:
  • Image Sensor: 1/1.3″ CMOS
  • FOV: 155°
  • Aperture: f/2.8
  • Camera FOV Mode: Standard, Wide, Ultra Wide
• Video Resolution:
  • 4K (4:3): 3840 x 2880@30/48/50/60fps
  • 4K (16:9): 3840 x 2160@30/48/50/60/100/120fps
  • 2.7K (4:3): 2888 x 2016@30/48/50/60fps
  • 2.7K (16:9): 2688 x 1512@30/48/50/60/100/120fps
  • 1080P (4:3): 1440 x 1080@30/48/50/60/100/120fps
  • 1080P (16:9): 1920 x 1080@30/48/50/60/100/120fps
• Operating Frequency:
  • 5.170-5.250 GHz
  • 5.725-5.850 GHz
• Maximum RF Output:
• Input Voltage: 7.4-26.4 V
• Mounting Options: 20×20mm and 25.5×25.5mm
• Dimensions:
  • Transmission Module: 33.5 × 33.5 × 13 mm (L × W × H)
  • Camera Module: 25.55 × 20 × 23.30 mm (L × W × H)
  • Coaxial Cable: 140 mm
  • 3-in-1 Cable: 100 mm
  • Antenna: 110 mm
• Weight:
  • Air Unit (exc. camera module): 15.6g
  • Air Unit (inc. camera module): 32.0g
  • Antenna: 2.1g each

Power Consumption

(xxx place holder – Data to be added soon…)

Can it Replace GoPro?

For casual FPV pilots, the DJI O4 Pro can absolutely replace a GoPro. The gap in image quality between the O4 Pro and high-end action cameras has narrowed significantly, and the weight savings are a huge bonus. However, for professional work, there are still advantages to using a separate action camera.

Like the O3, changing video settings on the O4 affects what you see in the goggles, including exposure, frame rate, and color, which can impact your flying experience. DJI has recently added a mode to the goggles to improve the look of the video feed when using D-Log M, which is a welcome addition. Also, it’s worth noting that 10-bit color is still not available on the O4.

Naked Version Possibility

Taking the O4 Pro apart is surprisingly simple—just remove four M2 screws.

This simple construction makes it feasible to decase the O4 Pro and turn it into a “naked” version to save weight, similar to the naked O3. While it will likely overheat faster without the casing acting as a heatsink, proper airflow might mitigate this issue. We’ll need to wait for someone to design 3D-printed or CNC spacers to make this mod happen.

Downsides

Despite its impressive features, the O4 Pro has a few drawbacks:

1. No audio: Neither the live feed nor the recordings include audio.
2. Limited high frame rate options: 100fps in 4:3 mode is only available in 1080p. This is disappointing compared to the O3, which supported 2.7K at 4:3. Pilots who prefer flying in 4:3 mode are forced to record in 1080p, which feels like a step back.
3. Onboard storage: The O4 Pro includes only 4GB of onboard storage, significantly less than the 23GB available on the O4 Lite. While it’s a nice backup, it would have been better to match the Lite’s storage capacity.

These shortcomings may not be dealbreakers for most pilots, but they are worth considering when deciding whether to invest in the O4 Pro.

Should You Choose the Lite or Pro?

The DJI O4 Lite is small, lightweight, and supports lower voltages, making it more suitable for smaller FPV drones like 3-inch or smaller quads. However, if your primary goal is to capture the highest quality footage on a small cinewhoop, the O4 Pro is the better choice. The additional weight is well worth it for the improved features and image quality.

The O4 Lite has slightly higher latency than the Pro, both in Normal mode and even in Race Mode (15ms vs. 20ms). The O4 Pro also boasts a wider field of view, making it better suited for image stabilization, and includes an SD card slot for storage expansion. It also supports more resolution options. If size and weight aren’t constraints, the Pro is the clear winner.

On the other hand, if weight saving is your priority, the Lite is a compelling option due to its compact design and shockingly light weight.

Should You Choose the Avata 2 or an FPV Drone with O4?

For advanced pilots, the O4 Air Unit Pro is the superior choice. It offers unmatched flexibility, allowing you to install it in any FPV drone you want. With no speed or height limits, it’s highly customizable, repairable, and more powerful than the Avata 2.

However, the Avata 2 is far more beginner-friendly. It has a much lower learning curve—there’s no need for building or soldering. Simply take it out of the box, and you’re ready to fly.

I’ve previously compared the Avata 2 to a custom-built 5-inch FPV drone, and most of the points remain relevant: https://oscarliang.com/avata-2-vs-5inch-fpv-drone/.

ND Filter

To achieve cinematic footage, ND filter is a must. Learn how to use ND filter in this tutorial: https://oscarliang.com/nd-filter-fpv/

Existing Avata 2 ND filters will fit the DJI O4 Pro camera. The official ND filters from DJI might be of great quality, but they are quite expensive. These filters can pop off and get lost during collisions, so opting for more affordable ND filters might be a good option for those on a budget.

Get it here:

SD Card Recommendations

SD cards are not included, so here are my recommendations: https://oscarliang.com/sd-cards-fpv/#GoPro-DJI-and-Other-HD-Cameras-4K-Videos. When capturing cinematic footage in risky locations, I always bring a few SD cards with me and swap them out after every flight. This minimizes the risk of losing all my footage if the drone is lost.

Final Thoughts

The DJI O4 Air Unit Pro sets a new standard for FPV systems, combining exceptional image quality, versatility, and performance. Its larger sensor, improved dynamic range, and onboard 4K recording make it a compelling option for both casual pilots and professionals. While it has some limitations, such as the challenging camera mounting, the O4 Pro is a solid upgrade from its predecessor, the O3. Whether you’re a freestyle enthusiast, a racer, or a cinewhoop builder, the O4 Pro offers features and performance that justify its price. For pilots looking to push their FPV setups to the next level, the O4 Pro is an excellent choice.

You can purchase the DJI O4 Air Unit Pro from the following retailers:

Edit History

• Nov 2024 – Leaked info published.
• Jan 2025 – Updated with official specs and info