The GoPro is great at what it does well - shooting action video. But, like a lot of cameras out there, it kinda blows at recording decent audio.
Sure, things have improved a lot with the newer versions of the GoPro (Hero5 and 6). They both have stereo mics on the front and a rear mic which can help with wind noise cancelling. But, ultimately, if you want great sound you have to add an external mic.
There are lots of options ranging from simple lapel mounted lavalier mics, to more feature rich and top audio shotgun mics.
It will depend on your purpose and budget, so I have separated them out into categories for you to easily find the one for you.
How To Add An External Mic To A GoPro
First things first. Before you run off and buy the best external mic you can find, you need to know the limitations and possibilities for your GoPro. Just like with tripods, not all mics and connectors are created equal.
Let's break it down into GoPro Hero 4 (and earlier) and then Hero 5 & 6. Because things have changed.
For all models of the GoPro above and including the Hero3, there are connection options. And, they all go via the mini-USB port.
Hero 5 and Hero 6
In all their wisdom, GoPro decided to change how things worked in these models. You now have to buy the official GoPro adapter and it is needed for both mini-USB and 3.5mm audio connectors.
There is also another plus and minus with this connector.
Plus: it now has a right-angle connector, which moves it out of the way a bit.
Minus: It is massive because it has some of the required tech inside it.
Hero 4, Hero3 Or Hero 3+
Things were kind of easier back in the day. So, if you have a GoPro Hero 4 or 3, you are in luck.
These models could connect to an external microphone either directly - via the mini-USB connector (normally for charging).
OR via an adapter, which coverts from mini-USB to a standard 3.5mm microphone connector. The adapter shown here is the official one, which is the best option - because many of the cheaper/non-official alternatives are a bit flaky. Feel free to try them, but there are so many bad reviews out there I don't feel comfortable listing any.
GoPro External Microphones
There are a tonne of options out there, so in this review I am only going to cover the best I can find and the ones that GoPro says work with their cameras.
Lavalier/Lapel mics are a great way to get voice audio without all the fuss of a big shotgun mic or attaching anything bit to your GoPro.
These are great if you plan on using your GoPro mounted to your bike or other moving object (even your helmet) and want to talk while recording.
The GoPro won't hear anything you say without such a mic, and you can get it close to your mouth in most cases.
The only downside of is that they come with a TRRS connector (3 rings) which needs an adapter (TRRS - TRS) to work with the GoPro connector.
Here is an example from Rode which is worth checking out.
This is one of the simplest options you are going to find.
An omni-directional lapel (lavalier) mic with a very long cable.
Not much that can go wrong with these kinds of mics, and this is one of the entry-level options you can buy (I own the Rode one, more on that later, but it's more expensive).
You also get a pop-wind filter which helps reduce the excess noise a lpt and the cable they give you has a huge extension, which can be super-handy if you mount point is miles away.
Rode once again come to the rescue when it comes to small and portable microphones that deliver great audio.
I own this one personally and use it for audio on my main camera for Youtube videos.
It beats my camera's audio by a mile and delivers great quality.
You can use it with their app on your phone (which they focus on) but you can also just plug it into any device that accepts audio input like the GoPro. You just need to grab the SC3 adapter like you do with all Lavalier mics to get them to work with the GoPro.
If you want top quality audio recording with lots of control, then a hotshoe mounted shotgun mic like those below is certainly the way you want to go. It's what top vloggers like Casey Neistat use on the go, and it will work well for a GoPro too. It just takes a little more work adjusting and on set up (with a mount) to make it all happen. But then again, nothing great comes easy!
One of the best and most popular external mics around is the Rode Video Micro.
It's compact, relatively cheap, high quality and easy to connect to your GoPro.
Rode is renowned for producing quality audio, so you know you are in good hands, and this thing comes with a windshield (awesome for recording while on the move).
It comes with a shock absorbing mount attachment, which you can attach to a shoe mount. For the GoPro, this means buying a case with a hotshoe mount on top. Some smartphones also have such mounts if you plan on using it on that too.
Shure are another great brand for capturing that audio you wish the GoPro could. This one is a very high-end option.
This is more of a serious model, with it's own power source, mechanical suspension for better noise isolation, and hotshoe mount for stability. It also connects with the 3.5mm jack, which is nice and easy.
Like the Rode above, this mic outputs only mono, but in two channels, so for those looking for stereo try the Sennheiser below.
Most people love this mic because of it's solid aluminium construction, ability to remove the microSD card (for separate recording) and the audio out (for monitoring). It also has a screen for easy adjustment of settings.
It is a little heavy though at around 10oz with batteries, and they don't last that long (10hrs or more). But with AA are easily replaced.
A dead cat windshield is also sold separately and adds quite a lot to the price.
Another solid choice not surprisingly comes from Sennheiser.
This is quite similar to the Shure mic above, having it's own battery (AAA) as a power supply and a shock mount to help reduce noise.
It also features an all metal housing, which is great news for a robust and long life (not that you are going to throw this around, but it helps).
The controls are not as fancy as those on the Shure, but there are enough to allow you to tweak the settings (for long and short distances) and also a wind setting to help reduce the noise we all love to hate.
All in all , this is a simple but quality mic for those that just want something that works.
Which Best GoPro Microphone For You?
One of the best solutions you can get is a shotgun mic. It provides you with great audio quality and control. If you just want to give that a try, and not break the bank, the Rode VideoMicro Compact is your best option. There are more expensive options in the Shotgun Mic section, but Rode produces awesome stuff at a reasonable price.
If you like the sounds of a lavalier/lapel mic to help capture your voice while you are doing you "thang", I would again go with the tried and true Rode smartLav+ which is one of the best and reasonably priced on the market. There are cheaper, but you pay for what you get.
Lots of options, lots of choices, but in the end it comes down to purpose and price!