How to Convert Video and Audio Formats on Mac

If you have ever downloaded a video only to find QuickTime refuses to open it, or exported a clip that your editor won't import, you have run into the format compatibility wall that every Mac user eventually hits. Converting video on Mac used to mean wrestling with command-line tools or paying for bloatware. This guide walks through why conversions are needed, what the output formats actually are, and how to handle the whole thing in a few clicks with Clipper.

Why People Convert Video on Mac

macOS has historically been picky about containers and codecs. QuickTime Player opens MP4 files without complaint but will often reject less common containers. iMovie and Final Cut Pro accept a narrower range of input formats than you might expect. When you want to AirDrop a clip to an iPhone or share something in iMessage, certain containers are a non-starter. And sometimes you just want the audio — stripping a video down to an M4A or WAV so you can listen on a walk is a perfectly common task.

Common reasons to convert video on Mac:

  • QuickTime and iOS compatibility — MP4 with H.264 video and MOV with H.265 play everywhere Apple.
  • Editor import requirements — some editors prefer specific containers or codec combinations.
  • Smaller file sizes — re-encoding at a lower bitrate shrinks storage footprint for archiving or sharing.
  • Audio extraction — pulling a podcast, lecture, or music video down to M4A or WAV for offline listening.

A Plain-English Guide to the Output Formats

Clipper's Convert tab produces exactly four output formats, all handled natively by macOS. Here is what each one is good for.

MP4 (H.264 video) is the universal container. It wraps H.264 video and AAC audio into a single file that plays on essentially every device, browser, and editing app. When in doubt, convert to MP4.

MOV (H.265 video) is Apple's own container. H.265 (HEVC) offers significantly better compression than H.264 at the same visual quality — useful for archiving or for projects destined for Final Cut Pro. Playback requires macOS or iOS; compatibility with non-Apple software is more limited.

M4A (AAC audio) is an audio-only format — MP4 without the video track. It is the native Apple audio format and offers excellent quality at small file sizes. Use it when you need the sound from a video but not the picture.

WAV (audio) is uncompressed audio. WAV files are large but lossless, making them ideal for professional audio workflows, sample libraries, and any scenario where you need to avoid re-encoding artefacts.

What About MKV, WebM, and MP3?

These formats are not available as Convert outputs — that is by design. The Convert tab is powered by AVFoundation, Apple's native media framework, which targets the formats above and keeps everything hardware-accelerated on Apple Silicon via VideoToolbox.

If you specifically need MKV, WebM, or MP3 as your file format, the right place to choose that is at download time, not at convert time. When you paste a URL in the Download tab, Clipper passes your format preference to yt-dlp, which can save videos in MKV or WebM containers and can extract audio as MP3. The choice of MKV/WebM/MP3 lives in the downloader — not in the converter.

Converting with Clipper

Clipper is a free, native macOS app built in SwiftUI. Its Convert tab uses AVFoundation — Apple's built-in media framework, hardware-accelerated via VideoToolbox on Apple Silicon — to transcode files. Because the conversion engine is part of macOS itself, there is nothing to install via Homebrew, nothing to type in Terminal, and no third-party codec packs required.

Clipper works on macOS 14 (Sonoma) and later, on both Apple Silicon and Intel Macs.

Step-by-Step: Convert a File in Clipper

  1. Open Clipper. On first launch it will download yt-dlp and ffmpeg in the background for its download engine — this takes a moment and only happens once.
  2. Go to the Convert tab. The Convert tab is where you bring your own local files; it is separate from the Download tab.
  3. Add your source file. Click the file picker or drag a media file into the queue. Clipper accepts common Mac-readable containers as input.
  4. Choose your target format. Use the format dropdown to select MP4, MOV, M4A, or WAV.
  5. Start the conversion. Hit Convert and Clipper hands the job to AVFoundation. Progress is shown in the queue; the output file lands in the same folder as your source by default.

That is the whole process — no flags, no codec strings, no Terminal window.

A Note on Quality: Re-encode vs. Remux

When you convert between formats, the process may either remux or re-encode the streams.

  • Remux means the video and audio streams are moved into a new container without touching the underlying data. It is lossless, extremely fast, and produces an identical-quality file. This is what happens when you convert a compatible source to MP4 if the video inside is already H.264 — the container changes, the picture does not.
  • Re-encode means the video is decoded and re-compressed using AVFoundation's hardware-accelerated codecs. This is necessary when the source codec does not match the target container. On Apple Silicon, VideoToolbox accelerates the encode so even long files convert quickly. Quality is preserved at sensible defaults.

For audio extraction to M4A or WAV, the audio stream is always decoded and re-wrapped (or re-encoded for WAV).

Batch Conversion

Clipper supports a queue, so you can add multiple files and convert them all in one go. Drop several files onto the Convert tab, set the target format once, and let Clipper work through them while you do something else. Each file is processed independently and output alongside the original.

Download Clipper

Clipper is free and open-source, with no subscription, no cloud upload, and no account required. Download the notarized DMG from clipper.decimahosted.com.

On first open, macOS Gatekeeper may show a warning because Clipper is distributed outside the App Store. Right-click (or Control-click) the app icon and choose Open, then confirm — you only need to do this once.

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