To compress a video, re-export it at a lower bitrate, and usually a lower resolution. The fastest free way on any device is a browser tool like the MobileStudio Video Compressor: pick a target size (say 25 MB for email), and it encodes the sharpest video that fits. On a computer, QuickTime (Mac), Clipchamp (Windows), and HandBrake (any) also work.
The short answer
| You're on | Easiest free way | Can you pick an exact size? |
|---|---|---|
| Any device with a browser | MobileStudio Video Compressor | Yes: 10, 20, 25 MB or custom |
| iPhone or iPad | iMovie: Share, then Options, then a lower resolution | No, resolution only |
| Mac | QuickTime: File, Export As, 720p or 480p | No, resolution only |
| Windows | Clipchamp: Export at 720p or 480p | No, resolution only |
| Mac, Windows, Linux | HandBrake (free, open source) | Close, with an average bitrate |
Why are video files so big?
A video's file size is roughly bitrate × length. A one-minute clip at 8 Mbps is about 60 MB. Phones record at high bitrates by default, so a short clip can run to hundreds of megabytes.
For a sense of scale, this is how much one minute of video takes, as listed on iPhone under Settings > Camera > Record Video:
| Recording setting | About this much per minute |
|---|---|
| 720p at 30 fps | 40 MB |
| 1080p at 30 fps | 60 MB |
| 1080p at 60 fps | 90 MB |
| 4K at 30 fps | 170 MB |
| 4K at 60 fps | 400 MB |
(Those are for the default High Efficiency format. Most Compatible is larger.)
So compressing means doing one or more of these:
- Lower the bitrate. Fewer bits per second, a smaller file. This is the main lever.
- Lower the resolution. 4K to 1080p is a quarter of the pixels, so each pixel gets more of the remaining bits.
- Lower the frame rate. 60 to 30 fps halves the frames. Fine for most things except fast motion.
- Shorten it. Half the length, half the size. Trim the parts you don't need first.
What size should your video be?
| Where you're sending it | Limit | Choose |
|---|---|---|
| Gmail (personal) | 25 MB total attachments (Google) | 25 MB, or less if you attach other files |
| Discord, free | 20 MB per file since August 2026 (Dexerto) | 20 MB |
| Slack, Teams, forms, quick shares | Varies | 10 MB is a safe, fast default |
Over Gmail's limit, Gmail doesn't fail; it swaps your attachment for a Google Drive link. If you need the video itself attached, compress it under the limit.
How do I compress a video in my browser?
This works on iPhone, Android, Mac, Windows, and Chromebook, and nothing is uploaded: the video is compressed on your own device.
- Open the MobileStudio Video Compressor.
- Drop in your video (MP4, MOV, or WebM).
- Pick a target size: 10 MB, 20 MB (Discord), 25 MB (email), or type your own.
- Leave Resolution on Auto. It picks the sharpest resolution your size can carry: a 30-second 1080p clip stays 1080p at 25 MB, but drops to 720p at 10 MB, because a clean 720p looks better than a blocky 1080p.
- Press Compress. If the file lands even slightly over your target, the tool re-encodes it smaller automatically.
- Download the MP4.
It's free, with no watermark and no account.
How small can a video get? Our test
We ran the same clip through the MobileStudio Video Compressor in Chrome on a Mac: a 30-second, 1080p, 60 fps test video with heavy motion and grain (56 MB), which is harder to compress than a typical phone video.
| Target | Result | Resolution Auto picked | Time |
|---|---|---|---|
| 25 MB | 23.1 MB | 1080p, 30 fps | 4 seconds |
| 10 MB | 9.2 MB | 720p, 30 fps | 2 seconds |
| 5 MB (480p chosen by hand) | 4.6 MB | 480p, 30 fps | 2 seconds |
Every result landed under its target, and the 25 MB version kept full 1080p. The lesson: for a 30-second clip, 25 MB is plenty for full HD, while 10 MB is the point where dropping to 720p looks better than squeezing 1080p.
How do I compress a video on iPhone?
iPhone has no "compress" button, but Apple's free iMovie app can export at a lower resolution:
- Open iMovie and create a new Movie project with your video.
- Tap Done, then the Share button.
- Tap Options and choose a lower resolution, like 720p or 540p.
- Tap Save Video.
To make every future video smaller, go to Settings > Camera > Record Video and choose 1080p at 30 fps, and make sure Settings > Camera > Formats is set to High Efficiency. For recordings of your own screen, see how to screen record on iPhone.
If you need an exact size (for Discord or email), use the browser compressor in an up-to-date Safari instead.
How do I compress a video on a Mac?
QuickTime Player (built in):
- Open the video in QuickTime Player.
- Choose File > Export As.
- Pick 1080p, 720p, or 480p.
Finder (built in, batch-friendly):
- Select one or more videos in Finder.
- Right-click and choose Encode Selected Video Files.
- Pick a lower setting, such as 720p, and click Continue.
How do I compress a video on Windows?
Clipchamp comes with Windows 11:
- Open Clipchamp and create a new video.
- Drag your video into the timeline.
- Click Export and choose 480p or 720p.
How do I compress a video with HandBrake?
HandBrake is free, open source, runs on Mac, Windows, and Linux, and the go-to when you want full control, as the video at the top of this guide shows.
- Open your video in HandBrake.
- Pick a preset such as Fast 720p30.
- For a target size, go to the Video tab, choose Avg Bitrate, and enter a number. For a target size in MB and a length in seconds: bitrate (kbps) ≈ size × 8,000 ÷ seconds, minus about 128 for audio. If you'd rather target quality than size, HandBrake's own guide recommends RF 20 to 24 for 1080p.
- Click Start.
How do I compress a video without losing quality?
Every compression throws some detail away. These keep the loss invisible:
- Lower resolution before bitrate. At small sizes, 720p looks cleaner than starved 1080p.
- Keep it short. Trimming costs zero quality. You can also speed up the slow parts instead of cutting them.
- Use H.264 MP4 for sharing. It plays everywhere. HEVC is about twice as efficient, but some Windows and Android players can't open it. (Why your MOV won't play.)
- Screen recordings compress well. Big still areas need little data, so app demos stay sharp at small sizes. Busy camera footage needs more room.
- Don't compress twice. Each re-encode loses a bit more. Start from the original file.
Are online video compressors safe?
Many online compressors upload your file to their servers. For private videos (work calls, family, unreleased products), use one that runs locally. The MobileStudio Video Compressor processes everything in your browser and never uploads the file.
Where MobileStudio fits
The compressor is one of our free tools. MobileStudio itself turns screen recordings of your app into polished product demos, with device frames, smooth zooms, and backgrounds, right on your phone. Get MobileStudio.
Quick FAQ
How do I compress a video to a specific size?
Use a tool that targets a size, like the MobileStudio Video Compressor: enter 20 MB or 25 MB and it fits the video under it. Most other apps only let you lower the resolution and hope.
What size can I send on Discord without Nitro?
20 MB per file, since Discord raised the free limit in August 2026. Before that, it was 10 MB.
Why is my video too big to email?
Gmail allows 25 MB of attachments in total. A minute of 1080p iPhone video is about 60 MB, so most clips need compressing first.
Does compressing a video reduce quality?
A little, since the file holds less data. Lowering the resolution only as far as needed keeps the difference hard to see, especially on a phone screen.
What's the best format for a small video file?
H.264 MP4 is the safest choice for sharing. HEVC (H.265) makes smaller files at the same quality but doesn't play everywhere.
Can I compress a video on iPhone without an app?
Yes. Open the MobileStudio Video Compressor in Safari; it runs in the browser with nothing to install.
