5 Ways To Trim Audio On a Mac

If you want to trim some time from the beginning or end of an audio file, you can quickly and easily do it with built-in macOS apps or free Apple-made apps you can download from the App Store, or a free third-party app. Each method has its advantages and disadvantages.
You can also watch this video at YouTube.
Watch more videos about related subjects: GarageBand (43 videos), iMovie (136 videos).

Video Transcript

Hi this is Gary with MacMost.com. Let me show you five different ways that you can trim audio files on your Mac. 
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Now if you have an audio file and you want to trim it, it's fairly easy to do using either software built into macOS or free software you can download. So let me show you five different methods. 
The first method is going to involve just using Quick Time Player. You may think of Quick Time Player as a video player. But it plays audio as well. Now I have three different types of audio files here. Now to open these in Quick Time Player you can drag them to Quick Time Player. You could launch Quick Time Player and choose File, Open or you can Control Click, two-finger click on the trackpad or right click on a Mouse, choose Open With and then Quick Time Player. Now it will open up and of course there is no video component. It's just audio. Quick Time Player allows you to trim video and if you open something that is just audio guess what? You can trim just the audio. So go to Edit, Trim or Command T and then you get this little interface here. You can even drag the right side to expand it a bit to make it a little easier to deal with. Then you can Trim a little off each side. You can Play and figure out exactly what you want to trim. Then click Trim and then File, Save will save a new copy with just that new area. This works with the most common types of audio files. So I can open up this MP3 here in Quick Time Player and trim. Or I can open up this Wave file in Quick Time Player and trim that. 
Now when it comes to audio you may right away turn to GarageBand which is a free app you can get from Apple in The App Store and it does a ton of different things. But you can use it to simply trim an audio file. So create a new empty project, like this. Choose just the Microphone there. You're not actually going to record anything new. Now I can drag one of these in here. Then you could very easily expand this so you can actually get very detailed on how you trim. Grab the bottom left hand corner, trim it in, and drag it back to the beginning and then grab the bottom right hand corner like that, and trim the stuff out from the end, and then you get what you want. You can go then to Share, Export Song to Disk, and export a new copy. One of the advantages to GarageBand, as you can see right away, is you can export in a variety of different formats and settings for those formats as well. Of course you can do other things in GarageBand as well like Filter it, Equalize it, and adjust things like the volume and all of that. GarageBand accepts a wide variety of different formats. So I can bring this MP3 in and I can bring this Wave in just as easily. 
Now a free app that you can download from the web is Audacity. A lot of people love to use this app for editing audio. Go to Audacityteam.org to download it directly from the source. In Audacity you can open up anyone of these files here. Then you can trim it a variety of different ways. I can select an area like this and just press Delete. Select another area, Delete. Then go to File and Export and export a variety of different formats. You can open up the MP3 or the Wave file just as easily. Of course there are a lot of different things you can do on Audacity as well including effects and easily editing out sections and all of that. 
Now here's an unusual way to do it. You can use the Voice Memos App. Of course the Voice Memos App is a great way to record something either on your Mac or your iPhone and through iCloud it ends up on your Mac. So what you're trimming could actually be something that is already here in Voice Memos. In that case it definitely makes sense to just trim it in here. You can go to Edit, Trim Recording or Command T, and now you can trim right here and get it to what you want and then Trim. But what about these external files? Well, if it is standard mpeg4 audio, which you can see that's what this M4A is here, Apple mpeg4 audio, then you can easily drag this in. You can actually add audio to Voice Memos which is a kind of useful thing all by itself. Because now it syncs across to all your devices. But you can also now go in and Trim this audio, like that, and now this is all trimmed and you can export back out by dragging out and you see how you get a new copy of it. It's a nice interface here with a nice big Wave form that you easily see and manipulate which could make it attractive to do this in Voice Memos. But one of the problems is that if it is not a mpeg4 audio file, like this MP3 you can't drag it in, the Wave file you can't drag that in. You can sometimes convert these files in the Finder by Control clicking on them and choosing Services and then there is Encode Selected Audio FIles and you can reencode this as a mpeg4 audio file. That works here with the Wave file but not with the MP3 file. 
But that's all a little bit of a hassle. So probably Voice Memos is best used for trimming when the audio is already in Voice Memos. 
Well how about doing it in iMovie. Let me show you how to do it first and I'll explain why you may want to do it this way. First create a new project and create a movie project. Now if you try to drag some audio into iMovie without anything in the Timeline it's going to force it into the special soundtrack area there at the bottom. That's fine. You could do it that way. Place it there and now when you play the movie you still get the audio. But the cool thing is you can now trim this really easily. So I could trim this a little bit there and a little bit here. Drag it back over to the Start and then when I'm done I can go to File, Share and then File. If I choose under Format Audio Only then I can actually even choose a variety of different formats here to export it as. 
Now there is some advantages to doing it in iMovie. One is, of course, you can really zero in here on the Wave form to see it pretty clearly to know where to trim. You could go to the Audio Settings here and adjust some things including Automatically Improve the Loudness, so kind of level it. You can go here to the Equalizer and add Equalizer Remove Background Noise. You can change the Speed really easily if you want. Speed it up slightly. There are some Effects that you could apply right here to change how it sounds. Of course you can further edit besides just trimming by doing things like going to Modify, Split-Clip like that. Moving sections around. But maybe the best reason for using iMovie is if you use iMove a lot. Maybe you don't have Audacity at all. Maybe you never use GarageBand. Maybe the Quick Time Player interface is too small to really trim what you want effectively. But you use iMovie all the time for editing video. So why not use your iMovie's skills to actually edit audio quickly and easily in the app that you know so well. 
So there are five different completely free ways to easily trim audio on your Mac. Hope you found this useful. Thanks for watching. 

Comments: One Comment

    Henning
    3 years ago

    Hi Gary,
    not to forget the 6th way: using quicklook in the finder app. Files supported by MacOS can be trimmed using the "trimm" button within the quicklook window, located left from the "share" button.
    Regards
    Henning

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