Video Compressor

Apple's own answer is iMovie: export the clip at a lower resolution. That works well, and it is covered below. This page is for when you need a specific file size, don't want to install an app, or are on a computer that isn't a Mac.

How to compress a video on iPhone

1. Open this page in Safari and tap the drop area above to choose the video.
2. Pick Target size (10 MB, 20 MB, 50 MB, or type your own) or Quality, which makes one pass at a balanced bitrate.
3. Pick a resolution cap. 1080p is the default and is never applied upward.
4. Tap Compress video and keep the tab open and in front. Phones pause background tabs, and a paused tab stops the encode.
5. Check the size and the preview, then tap Download MP4.

The same page works on Android, Windows and Mac, as long as the browser can encode video with the WebCodecs API. On iPhone that means Safari on iOS 16.4 or later, according to MDN's VideoEncoder reference. Firefox for Android does not support it. The tool checks when it loads and says so before you pick a file.

Apple's built-in ways to get a smaller video

Apple's Compress a video on iPhone page centres on one route: export the clip from iMovie at a lower resolution. If the file is still too large, Apple suggests trimming it shorter, and camera settings can make future videos smaller. The iMovie steps are written for an iPhone 12 or later on iOS 26 or later, and Apple notes they vary on earlier versions.

Apple gives these approximate sizes for one minute of video, and says 540p suits social media and 360p suits text messages. We checked the page on 30 September 2026.

For smaller files from the start, Apple suggests recording below 1080p HD, turning off HDR Video and keeping High Efficiency selected. Those settings only help future recordings; this tool and iMovie are for the videos you already have.

Target size vs quality: what the settings change

Target size works backwards from the number you pick. It divides the size by the video's length to get a bit budget, sets aside 128 kbps for audio and 5% for the MP4 container, and encodes. It then measures the real file and retries at a lower bitrate if it came out too big, up to four attempts, each listed with its measured size.

For example, a 20 MB target for a one-minute clip starts at about 2.5 Mbps of video. The lowest bitrate it will try is 150 kbps, so a very small target for a long clip can miss. The tool warns you before you start when that is likely.

In our own test on a Mac in Chrome, a one-minute 4K HEVC test clip of 216.6 MB reached a 20 MB target on the first attempt, at 1080 by 1920, in about nine seconds. That clip was a synthetic test pattern on a desktop computer, so real footage and phone chips will give different times and sizes.

Resolution

The cap applies to the short side, so 1080p on a portrait phone video gives 1080 pixels wide by 1920 tall. At low bitrates a smaller picture usually looks cleaner than a large, blocky one, so try 720p when you're aiming for a small file. For the sizes phones record in, see the iPhone aspect ratio guide. For upload targets, see YouTube video sizes.

Bitrate

Bitrate is how many bits each second of video gets, and it decides the file size more than anything else. The video bitrate calculator explains the maths and works out sizes for any length. This tool re-encodes to H.264, which is less efficient than the HEVC many iPhones record, so a low target matters more than it seems.

Audio

The original audio is copied into the new file unchanged when an MP4 can hold it, which is the case for the AAC audio phone cameras usually record. There is an option to re-encode it to AAC at 128 kbps instead. The tool can't remove the audio track.

HDR iPhone video and why it can look washed out

HDR video stores brightness and colour with more precision and a wider range than standard video. When the tool finds an HLG or PQ transfer in the file, the HDR formats phone cameras use, it flags the clip as HDR before you compress.

The compressed copy is standard-range 8-bit H.264. The browser maps the HDR picture down, and bright highlights and saturated colours can look flatter or slightly washed out next to the original. If colour matters more than size, keep the original file, or turn off HDR Video before recording future clips, as Apple suggests for smaller files.

What this compressor does and does not do

It reads MP4 and MOV files, including HEVC where the browser can decode it, and writes an H.264 MP4 with the audio kept. The file is read in pieces rather than loaded whole, and the smaller copy is built in memory until you download it. It keeps portrait video portrait.

It does not trim, cut or edit, output HEVC, read WebM or other containers, or compress several files at once. Very long 4K clips can still be too much for a phone browser, so if the tab reloads, trim the clip in Photos first or choose 720p. To turn a short clip into a GIF instead, use the video to GIF converter.

Video compressor FAQ

How do I compress a video on my iPhone?

Open this page in Safari, tap the drop area and pick the video. Choose a target size or a resolution, tap Compress video, and keep the tab open until it finishes. Then download the MP4. Apple's own route is to export the clip from iMovie at a lower resolution.

How do I make a video small enough to email?

Find your email provider's attachment limit and aim below it. Gmail's help page puts the limit for personal accounts at 25 MB and turns bigger attachments into a Google Drive link. The 20 MB preset here leaves headroom under that limit. For other providers, check their own help pages.

What does compressing a video actually do?

It re-encodes the picture with fewer bits per second and, if you choose, fewer pixels. That throws away detail you are least likely to notice, so the file shrinks and the quality drops a little. This tool writes H.264 video in an MP4, which almost any phone, computer or app can play.

Will my HDR iPhone video look different after compressing?

It can. HDR video carries a wider range of brightness and colour than an 8-bit H.264 file can hold, so the browser maps it down to standard range. Highlights and saturated colours may look flatter or slightly washed out. The tool flags HDR clips before you start.

Is my video uploaded?

No. The video is read, decoded and re-encoded inside your browser tab, and the compressed copy is built in the tab's memory. No part of the video is sent to a server, so it never costs you upload data and works on clips you would not hand to a website.