How to Compress a Video on Mac (No Extra Apps)

A five-minute screen recording can easily weigh a gigabyte — too big to email, slow to upload, absurd to archive. macOS can shrink it to a fraction of that with tools already installed: QuickTime's export presets and a right-click encoder hiding in Finder. Both write a new file, so your original is never at risk. Here's which to use and what actually makes video files big.

QuickTime: pick a smaller resolution

1. Open the video in QuickTime Player.
2. Choose File → Export As — you'll see 4K (if the source is 4K), 1080p, 720p, and 480p.
3. Pick the smallest resolution that still serves the purpose. For screen recordings destined for a chat message or bug report, 720p is usually plenty; for anything watched full-screen, 1080p.
4. In the save dialog, look for the "Smaller File Size (HEVC)"-style checkbox on the higher presets — ticking it encodes with HEVC (H.265), which lands at roughly half the size of the default H.264 for similar quality.
5. Save. The export runs with a progress bar and writes a new .mov; the original stays exactly as it was — deleting one or the other is your only cleanup.

Finder: the right-click encoder nobody knows

Finder has a built-in media encoder that skips QuickTime entirely — and it can batch:

1. Select one or more videos in Finder.
2. Right-click → Encode Selected Video Files (if it isn't in the top level of the menu, it's under Services).
3. In the dialog, choose a Setting — resolutions paired with H.264 or HEVC, plus an audio-only option — and where to put the results.
4. Click Continue. Encoded copies appear next to the originals.

This is the tool for "compress these nine clips while I get coffee." The same dialog is also the fastest built-in converter — it happily turns odd QuickTime output into more compatible files.

What actually shrinks a video

• Resolution is the big lever. 1080p is a quarter of 4K's pixels; going from 4K to 1080p routinely cuts size by 60–75% before any codec cleverness.
• Codec is the second lever. HEVC ≈ half of H.264 at similar quality. The tradeoff is compatibility: anything Apple from the last several years plays HEVC fine, as do modern Windows and Android — but ancient corporate laptops and some web tools still prefer H.264. When in doubt about the audience, H.264 at a lower resolution is the safe compromise.
• Content matters. Screen recordings — mostly static pixels — compress spectacularly well; handheld video of moving scenes compresses least. This is why your 1 GB recording can drop to 80 MB while a 1 GB holiday video only halves.
• Length, obviously. Trimming the dead air first compounds every saving after it.

A sane default recipe

For the everyday case — a screen recording that must be shared: trim the ends, then Export As → 1080p with HEVC ticked. If the recipient's setup is a mystery or the upload target is picky, re-run at 1080p H.264 instead. Keep the original until the recipient confirms it plays; that habit costs nothing because every method here leaves the source file untouched.

Recording-specific tricks

If what you're compressing is always screen captures, you can also record smaller in the first place — resolution, frame rate, and format choices at capture time. See how to compress a screen recording for that end of the pipeline.