MacMost Now 866: Compress Video and Audio With the Finder

The OS X Finder offers simple options to compress video and audio files. You can use this to quickly re-compress these files before archiving them or sending them to others. These simple functions only work with some file types and offer limited options.

Video Transcript
Hi this is Gary with MacMost Now. On today's episode let's take a look at using the Finder to compress video and audio.

This is something fairly new to Mac OS X and it makes a common task much easier. You can select either an audio or video file. Let's start with a video file. You can Control click or right click or two finger click depending upon your device on it.

I'm going to Control click and get the Context Menu. One of the options in the Context Menu is Encode Selected Video Files. When you select that you get a little dialogue that gives you some options. Here it comes. You get some basic encoding options. Nothing too special. Pretty much what you get inside of Quick Time Player but you don't have to run Quick Time Player to use it.

You can recompress this video. You can do at 480p for instance to make it smaller. You can just say audio only because I just want the audio from the video. You can encode it either for greater compatibility of higher quality. So let's make it very compatible at 480p. Then I can select where to save it or just say Same as the source. I can even say delete the source. So I just want to compress it and get rid of the original.

Hit continue and what will happen, it will take a little bit of time, and you see the new one appear there and that's going to be a M4V file and if I select it, you can see the original is 2.9 MB, and the new version is going to be smaller. It is going to be 5.2 MB. Either one will look very similar but this one will be a lot smaller to use. Very handy if you take a video with your iPhone or your camera and it's a big high-def video and you just want to quickly compress it to share it with somebody.

Now likewise we can do the same with an audio file. So we are going to take, in this case, a MP3 file. Control click on it and it will say Encode Selected Audio Files. You get a slightly different set of options. I can set the quality for it here and the lowest quality will be a Spoken Podcast. So I can compress it and save it back out.

I can so the same for some audio files. So let's select this wav file for instance here. I'm going to recompress it into something more compatible and a smaller size. I can Control click, Encode Selected Audio Files, and now it gives me several options here. I will stick with high-quality in this case. Continue and I get a m4a file. It is a little more compatible than the wav file there and I can see that it is smaller too. 20 KB as opposed to 86 KB. It is a short file but you can imagine a longer piece of audio will get a lot more benefit out of that compression.

You can go to this original file here and let's Control click on it. Encode the video files and let's select that we want it to go audio only. Now we continue and we will actually get a m4a file, an audio file that is just the audio from that video.

So word of warning. This doesn't always work. It has to be a certain file format to begin with. So sometimes you get a file, like say a MP3 file, and you try to compress it. It won't do it. Usually when this happens it's because the file is already in a good compressed format. So for instance taking a wav file or an aif file in audio and using this will work but taking a MP3 usually doesn't work then usually it doesn't need it.

There is not much more to it than that. It is pretty simple. You don't get many options but it is a handy way to be able to recompress audio and video if you want to send somebody a copy or just archive it yourself not at full quality.

You get some more options if you are using Quick Time Player and then of course there are tons of apps out there that will do complex conversions. You can always use iMovie and Final Cut Pro to do it as well. This is a very simple tool you can use in the Finder without using any other apps.

I hope you found this useful. Until next time this is Gary with MacMost Now.

Comments: 8 Responses to “MacMost Now 866: Compress Video and Audio With the Finder”

    6 years ago

    Gary check @ 1:17 to1:30 on this video. You said the compression from 2.9 to 5.2MB indicating that 5.2MB was smaller. Not being critical just though you may want to correct that.

    Thanks for all your great tips and easy to understand teachings.

      6 years ago

      I think people are smart enough to get the idea.

        Robert Regaldo
        6 years ago

        Gary, a couple quick corrections:
        1) These tools are not part of the Finder application, they are system Services created with Automator. You can edit their workflows and expand them to accomplish more.
        2) The reason some formats do not compress is that legacy QuickTime formats are not supported.

        For more info, visit:


        6 years ago

        But it’s larger.. not smaller.. so I don’t get it?

          6 years ago

          Bad example. I was compressing a tiny video file that didn’t need compressing. Try it yourself with a larger video file. The idea isn’t how it compresses the one example video file, it is how to use the commands.

            Ken Olah
            6 years ago

            Gary, it’s not about how smart we are but our level of tech capability. We value MacMost because it’s educational. I would have thought a small video file would have become even smaller if it was compressed correctly. So, was 420 the right encoding? I’m also unsure whether compressing affects quality. Finally, I’m unsure of the purpose. Is it to save space or to make it easier to send to someone. If it’s about space, presumably one ought to delete the original, but is there a risk to that?

              6 years ago

              Compressing does affect quality. It is a trade-off between quality and file size. The goal is to save space and also to make it easier to transfer over a network (send to somebody).
              Whether you delete the original depends on what the video is and what you are doing. A precious home video of your child taking first steps? You’d want to compress it to make a new version to send to someone, but you definitely want to keep the original as the one you view and save for yourself.

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