How to make a video file smaller without ruining it
The best way to a smaller video is a lower resolution chosen at download time. When that's not possible, here's how to compress well.
2 min read · Updated
A video too big to email, upload or fit on your phone needs shrinking. How you shrink it decides whether the result looks nearly identical or noticeably worse. The biggest savings, with the least visible loss, come from choosing the right resolution — ideally before you download at all.
Start with the smallest file that looks good
Every re-compression loses detail, so the best compressed file is one that was never compressed twice. If the video is online, download a smaller version directly: 720p is plenty for a phone, and often a third of the size of 1080p. Every option on the YouTube downloader shows its file size, so you can pick the one that fits.
For talks and podcasts published as video, audio only is smaller still.
What actually makes a video file big
Four things drive size, in roughly this order:
- Bitrate — how much data per second. The single biggest factor.
- Resolution — more pixels need more data to look good.
- Frame rate — 60fps carries twice the frames of 30fps.
- Length — size grows in step with duration.
How much space and data video uses shows how to estimate size from bitrate and length.
Compressing with HandBrake
HandBrake is free and handles most cases well:
- Open the video in HandBrake.
- Pick a preset one step below the source — for a 1080p video, Fast 720p30.
- Under Video, keep the H.264 encoder for compatibility and use Constant Quality; a value around 22–24 shrinks well while looking clean.
- Start the encode and compare the result with the original on the screen it will be watched on.
Compressing with FFmpeg
This command scales to 720p height and compresses with a quality-based setting:
ffmpeg -i input.mp4 -vf scale=-2:720 -c:v libx264 -crf 23 -preset slow -c:a aac -b:a 128k output.mp4
Raise -crf for smaller files (and lower quality); lower it for the opposite. H.265 (libx265) makes files smaller again at the same quality, if the devices that will play it support H.265.
What to avoid
A few habits make compression look worse than it needs to:
- Compressing the same file repeatedly — each pass adds blockiness.
- Shrinking below the resolution of the screen it'll be watched on.
- Very low bitrates on fast motion — sport and games break up first.
- Online compressors that ask you to install something or sign in for a basic file. Are online video downloaders safe? covers the warning signs.
Sometimes you don't need to compress at all
If the goal is sending the file, a share link from cloud storage avoids size limits without touching quality. How to send large video files compares the options.