Hollyland Mars X HDMI Wireless Transmitter Full Review A Look at the Mars X wireless HDMI for mobile devices

A couple of months ago we received the Mars X wireless HDMI transmitter unit from Hollyland. After reviewing its bigger brother the Mars 300 PRO back in September 2020 we wanted to test the Mars X immediately but we had to wait for our new Samsung tablet to arrive so we had to postpone things a little bit.

The Mars X is a much simpler system than the Mars 300 Pro and most other wireless HDMI systems it has a single transmitter and it is designed for mobile users who want to work with smartphone and tablet apps instead of monitors.

While you can work with the app when using the Mars 300 Pro alongside a normal monitor, with the Mars X you only have the app as an option but you can still connect up to 3 devices at the same time (Android or iOS) which is very convenient.

Mars X – wireless HDMI to mobile devices

Build and design

The unit is 9cm / 3.5 inches long (15cm /6” with the antennas open) and 4.5cm / 1.7” wide and weighs under 120 grams / 4.2 OZ. Unlike other wireless transmitters, It has a built-in 1300 mAh battery which you can charge (or power on the fly) via either USB-C or micro-USB cable from a wall charger or external power bank.

The Mars X has a very simple but effective design. It includes a small OLED screen showing the battery levels and connection type/status. On/off button which can also be used to switch channels, the two USB ports mentioned), HDMI connection and two ¼” 20 – one on the back and one on the bottom. Finally, you have the two antennas which can be opened for better reception.

The unit comes with a USB-C to USB-C charge cable, cold shoe mount, pouch, and a manual.

Using the Mars X

Using the Mars X is extremely straight forward. Make sure that the internal battery is charged and connect an HDMI cable from the unit to the camera (do note that you will need to supply your own cable for this).

Turn the unit on and connect to the WIFI network the Mars X creates on your mobile device (the password is 1 to 8). Download the Holyview app and connect to the Mars X and start working – it is as simple as that and with our Samsung Galaxy S6 tablet, it worked out of the box the first time.

We have already covered the Holyview app on our Mars 300 Pro review (you can check it out here) but since that review, Holyview did update the app several times and for us, it seems to work very well on the Samsung S6 as and is still the best and most feature-rich camera monitoring apps that we have used to date.

It includes almost all of the advanced options of a professional monitor such as waveform, histogram, focus peaking, zebras, frame zone, false colors, mono-color, and LUTs (including some common built-in options for Canon and Sony and you can load your own).

The Mars X app does play sound coming from the camera but unless we have missed something, we could not find the audio meters (we will be checking this one with Hollyland and updating the article accordingly).

You can also take a screen gab and even write on it (really cool) or record to the mobile device which can be very useful as a sort of quick lower resolution version for sharing with clients for example.

Mars X performance (latency, range, and battery life)

We were pretty impressed with the performance of this little unit. The official 70ms latency seems not too far off especially at close range on a good 5Ghz WIFI and although we do not suggest using this for any fast action focus pulling, for normal speed monitoring at a range of several meters like we normally do in our studio it works perfectly fine.

Talking about range, the official range is set at over 100m or about 300 feet when used in an open space with no interference. We tested the unit in a much more confined space with 2 heavy metal doors in the way and several walls and were able to get a signal without significant drops at about 15 meters which is actually pretty impressive (and of course also depends on our own network and the tablet we used).

Finally, battery life. This is maybe the biggest drawback of the unit. With such a slim size there is not a lot of room for a battery and the battery life that we tested was about one hour which means that for most shots you will need to have the unit connected to a power bank. Fully charging the unit took us just over 2 hours.

The Mars X is also completely silent unlike many other wireless HDMI units and does not get extremely hot even after long use.

So, who is the Mars X designed for? The answer is anybody who needs to remotely monitor the image from a camera on a mobile device without too much hassle and without spending to much on expensive gear including both the unit itself and a monitor, batteries, etc.

The only thing that could make the Mars X and Holyview experience even better would be a way to control the camera from the app. It’s not clear if this is possible with the current hardware of the unit but maybe this will come in the next version of this product.

Mars X – compact and simple to use

Mars X on Sony A7R IV


The Mars X is a fun little unit that can be very useful on the go. While some camera manufacturers have apps that can show the image from the camera in real-time, none of them has anywhere near as many monitoring options as the Holyview app and can’t work with 3 devices at the same time (although they do have the option to change camera settings and record).

The only major drawback that you need to consider with this device other than the obvious fact that you are limited to working with iOS/Android devices is the battery life which means that for any kind of real work you will always have to connect this to a power bank.


Pricing is very much the cherry on top of this unit. At just under $180 this unit is extremely affordable compared to other wireless HDMI solutions and is less than half the price of the Mars 300 PRO which is not very expensive on its own.

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Art Podolski is a photographer and video editor with an interest in marketing, technology and all things cinema. After shooting wedding photography for 5 years, he transitioned into creating video content for online projects and collaborating with various production companies.

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