How to compress a video on Mac without losing quality

A two-minute clip from an iPhone can easily be 300 MB or more, and a screen recording isn’t much better. That’s too big for email, too big for most chat apps, and slow to upload anywhere. The good news is that most videos can lose 60–80% of their size with no difference you’d notice on a phone or laptop screen. This guide shows you how, starting with the free tools already on your Mac.

How video compression works (in two minutes)

You don’t need to understand codecs to compress a video, but three ideas make every setting below easier to choose.

• Bitrate is what decides the file size. A video’s size is roughly its bitrate multiplied by its length. As a rule of thumb, megabytes ≈ bitrate in Mbps × seconds ÷ 8. A 60-second clip at 3.3 Mbps comes out at about 25 MB.
• Resolution changes how many pixels need storing. Going from 4K to 1080p means a quarter of the pixels. Most people watching on a phone won’t see the difference, which is why lowering the resolution is the quickest way to shrink a file.
• The codec is how efficiently those pixels are stored. H.264 plays on almost everything. HEVC (also called H.265) gives similar quality at a noticeably smaller size, and plays on every Apple device from the last several years, but some older Windows PCs need an extra codec for it.

Phone cameras and screen recorders record at very high bitrates so they never drop detail while capturing. That headroom is exactly what compression takes away, which is why the first pass usually saves so much.

Method 1: Finder’s Encode Selected Video Files (free, built in)

This is the most capable free option and most people don’t know it exists. It works on one video or a whole selection at once.

1. In Finder, select one or more videos.
2. Control-click (or right-click) the selection and choose Services › Encode Selected Video Files. On some setups it appears under Quick Actions or at the bottom of the menu.
3. In the Setting menu, choose a preset:
   • HEVC 1080p for the best size-to-quality balance on Apple devices.
   • H.264 1080p or H.264 720p if the video will be played on Windows PCs, older devices or uploaded to a website.
   • H.264 480p for the smallest possible file, when quality matters less than size.
4. Leave Destination as Same as source file, and make sure Delete source files after processing is off, so you keep your original.
5. Click Continue. The compressed copy appears next to the original as a .mov file.

The labels are “up to” sizes: a widescreen video encoded at 480p comes out at 640×360, because the aspect ratio is kept.

Method 2: QuickTime Player’s Export As

QuickTime Player gives you the same idea with fewer options, and it’s handy when you already have the video open.

1. Open the video in QuickTime Player.
2. Choose File › Export As and pick a resolution: 4K, 1080p, 720p or 480p. Sizes larger than the original are greyed out.
3. For 4K and 1080p, choose a Format: Smaller File Size uses HEVC, Greater Compatibility uses H.264.
4. Name the file and click Save.

Two limits to know: QuickTime always saves a .mov file (it can’t export MP4), and there’s no bitrate or target size control. If 720p is still too big, all you can do is drop to 480p. To trim the ends before exporting, use Edit › Trim first, which is often the easiest saving of all.

Method 3: iMovie, when you want a size estimate

iMovie is free from the App Store and shows you the estimated file size before you export, which makes it good for hitting a limit.

1. Create a new movie and drag your clip onto the timeline. Trim it if you like.
2. Choose File › Share › File.
3. Lower the Resolution (720p is a good choice for sharing), and set Quality to Medium or Low. Choose Custom to get a bitrate slider; the estimated size updates as you move it.
4. If you see a Compress option, Better Quality is worth the extra wait. Click Next and save.

iMovie is more steps than the other methods, and it isn’t great for batches, but the live size estimate is useful when you must stay under a limit.

Method 4: Photos, for videos in your library

If the video is in the Photos app, select it and choose File › Export › Export 1 Video. The Movie Quality menu offers 480p, 720p, 1080p and 4K. Choose 720p or 1080p to get a smaller copy without touching the original in your library.

Method 5: Terminal, for batches and scripts

macOS includes a command-line tool called avconvert that uses the same presets as Finder. For example, to make an HEVC 1080p copy:

avconvert -s input.mov -p PresetHEVC1920x1080 -o output.mov --progress

Other useful presets include Preset1280x720, Preset640x480 and PresetMediumQuality. Run avconvert --help to see the full list, plus options to trim with --start and --duration.

How to compress a video for email

Email has hard limits, and they’re lower than most people expect:

Because attachments grow by about a third when they’re encoded for sending, aim for a file comfortably under the limit: around 18–20 MB is safe for most services.

To get there with free tools, try 720p H.264 in Finder or QuickTime first, check the size, and drop to 480p or trim the clip if it’s still too big. With the bitrate formula above you can work it backwards: a 2-minute clip that has to fit in 20 MB needs a total bitrate of about 1.3 Mbps, which means 480p or a shorter clip.

If you use Apple Mail with iCloud, Mail Drop is often easier than compressing: Mail offers to send large attachments as a download link, up to 5 GB.

The fiddly part of all this is guessing. MightyBench’s Compress Video has a Target size mode with presets for email (25 MB) and chat (16 MB): you type the size, and it works out the bitrate so the file fits first time. It keeps the original resolution and frame rate, writes an MP4 that starts playing before it’s fully downloaded, and works through a whole batch at once.

How to compress a video for WhatsApp, Slack and social media

Chat apps and social networks recompress whatever you upload, often harshly. You get better-looking results by sending them a file that’s already the right size, so their compression has less to do.

• WhatsApp and iMessage: both compress videos you send in the normal way. Sending a 720p H.264 MP4 keeps quality more predictable. To send the original untouched, send it as a document/file instead.
• Slack, Discord and Teams: upload limits vary by plan. A 1080p video at a moderate bitrate is usually fine; compress long recordings first.
• Instagram, TikTok, YouTube: upload the best quality you have that’s within the platform’s limits. These platforms re-encode everything, so compressing hard first only stacks two rounds of quality loss.

Tips to keep quality while shrinking a video

• Trim first. Cutting 30 seconds of dead air saves more than any setting, with no quality cost. QuickTime’s Edit › Trim or MightyBench’s Trim Video can cut without re-encoding.
• Don’t compress twice. Every re-encode loses a little. Go back to the original each time you try a new setting.
• Pick HEVC for Apple-only viewers. If everyone watching uses an iPhone, iPad or Mac, HEVC gives the most quality per megabyte.
• Pick H.264 for everyone else. If you don’t know what the recipient uses, H.264 MP4 is the safe choice.
• Keep the frame rate of the original. Halving it from 60 to 30 fps can save space for screen recordings, but makes motion look choppy in sports or games.
• Match resolution to the screen. 1080p is plenty for laptops; 720p looks fine on a phone in a chat thread.

If you need an MP4 rather than a MOV (some websites and Windows apps insist), see Convert Video, or use HandBrake, a free open-source converter. HandBrake’s Constant Quality setting is the one to use; its documentation suggests values around 20–24 for 1080p with the x264 and x265 encoders, where a lower number means better quality and a bigger file.

Frequently asked questions

How do I make a video smaller on my Mac for free?

Control-click the video in Finder and choose Services › Encode Selected Video Files, then pick a smaller preset such as HEVC 1080p or H.264 720p. QuickTime Player’s File › Export As and the Photos app’s export also let you choose a lower resolution, all for free.

Can QuickTime compress a video?

Yes, but only by lowering the resolution or switching to HEVC. Choose File › Export As, pick 1080p, 720p or 480p, and for 1080p choose Smaller File Size. QuickTime has no bitrate or target size control, and it always saves a .mov file.

How do I compress a video to send by email on a Mac?

Aim for a file under about 20 MB. Export it at 720p or 480p using Finder or QuickTime, trim it if it’s still too big, or use a compressor with a target size setting. If you use Apple Mail, Mail Drop can send files up to 5 GB as a download link instead.

Does compressing a video reduce its quality?

Technically yes, because re-encoding discards some data. In practice, a sensible compression of a phone video or screen recording is hard to tell from the original, because those files are recorded at far higher bitrates than you need for viewing.

Should I use H.264 or HEVC?

Use HEVC when the video will be watched on Apple devices, since it’s smaller at the same quality. Use H.264 when you don’t know who will watch it, or when it’s going to Windows PCs, older devices or a website, because it plays almost everywhere.

Why is my iPhone video so large?

iPhones record at high bitrates, often in 4K and sometimes at 60 fps, so nothing is lost while you film. That headroom is why phone videos shrink so much when compressed. You can record smaller files in the first place under Settings › Camera › Record Video on the iPhone.

Does zipping a video make it smaller?

Hardly. MP4 and MOV files are already compressed, so a zip file of a video is usually only a percent or two smaller. Re-encoding at a lower bitrate or resolution is what makes the real difference.

What is the best video compressor for Mac?

For free, Finder’s Encode Selected Video Files is the quickest built-in option, and HandBrake gives the most control. If you compress videos regularly and want to hit an exact size in one go, a dedicated app with a target size mode, such as MightyBench’s Compress Video, saves the trial and error.