Video Compressor

Make a video small enough to send or upload. Choose a size in MB and a maximum resolution, and the video is re-encoded as an MP4 on your own device — no upload, no sign-up, no watermark.

How to compress a video

1. Choose a Target size — 8, 10, 25 or 50 MB, or any whole number from 1 to 2000 typed into the Custom box — and a Max resolution. 25 MB and 720p are selected to start with.
2. Drop the video into the box, or tap Choose videos. You can add several; they are compressed one at a time, each row showing a percentage and a Cancel button.
3. Press Play to check the result, then Download the MP4. If no compressed version comes out smaller than the original, you get your original back, and the row says so.

How the target size is reached

A video's file size is roughly its bitrate multiplied by its length, so the compressor works backwards from the size you ask for. It divides the target by the duration, keeps 8% in reserve for the MP4 container and encoder overshoot, sets aside 96 kbps for the sound, and gives everything else to the picture. A one-minute clip with a 25 MB target, for example, gets about 3.3 Mbps in total and just under 3 Mbps for the picture.

If the finished file still comes out over the target, the row reads “Over the target, compressing again…” and the video is compressed again, up to two more times. Usually the picture bitrate is cut in proportion. But hardware encoders have a floor — at 1080p some won't go much below 1 Mbps whatever they are asked for — and when that happens the tool lowers the resolution instead, since the setting is a maximum; the row then says so. The same happens when a pass comes out no smaller than the original, which can occur with an efficiently encoded video that is only slightly over the target. If even the third attempt is too big, you get the smallest attempt, marked in red as still over the target — or your original, if no attempt was smaller than it — with a note suggesting a lower resolution or a larger target. Sizes in the list are counted the same way as the target, 1 MB = 1,000,000 bytes.

Why resolution matters as much as size

Every pixel needs bits. At a fixed file size, fewer pixels means more data for each one, so a 720p video usually looks cleaner than a 1080p video squeezed into the same number of megabytes. That's why 720p is the default: it's sharp on a phone and in a chat window, and it leaves the encoder room to work. Choose 1080p when the target is generous, 480p when it is tight or the video is long.

Resolution is measured on the short side, so 720p means up to 1280×720 for a landscape video and up to 720×1280 for a portrait one. Videos are only ever scaled down — a 480p clip stays 480p even if you choose 1080p.

What bitrate a target size gives you

The table shows the picture bitrate the compressor aims for at 720p, the default setting. The 8% reserve and the 96 kbps for sound have already been taken off.

The ceiling works out to 0.2 bits per pixel per frame at 30 frames a second: about 5.5 Mbps at 720p and 12.4 Mbps at 1080p. Past that point extra data mostly adds size, so a short clip with a large target comes out well under it. With 1080p selected and a source at least that sharp, the capped cells above become 6.04, 12.17 and 6.04 Mbps.

As a rough guide, a few hundred kbps is enough for a talking head or a slide recording at 480p, 1–2 Mbps gives a decent 720p picture of everyday footage, and fast motion — sport, games, shaky handheld shots — needs more. When the numbers get small, lower the resolution. If the picture would get less than 100 kbps, the tool stops and tells you the smallest target that will work.

Why phone videos are so big

Phones record at high bitrates to keep as much detail as possible. An iPhone lists how many megabytes a minute each recording mode takes under Settings › Camera › Record Video, and at 4K and 60 frames per second it runs to hundreds of megabytes a minute. Compare that with a 25 MB target for a one-minute clip, which allows about 3.3 Mbps in total.

Three things decide the size of the compressed file: the target you set, the resolution and the length. Frame rate is left as it is, so a 60 fps recording stays smooth but shares its bits among twice as many frames as a 30 fps one. If a 60 fps clip looks rough at your target, step the resolution down.

Why the result is H.264 MP4 — and when it won't shrink

H.264 video in an MP4 file plays practically everywhere: older Windows PCs, Android phones, smart TVs, email previews and upload forms. HEVC (H.265) and AV1 can be smaller at the same quality, but plenty of devices and websites still can't play them, and browsers can't always encode them. For a file whose whole purpose is to be sent somewhere, compatibility wins.

That choice has a side effect with iPhone videos. With the camera format on High Efficiency, the default, iPhones record HEVC, so the original is already compact. Turning it into H.264 at the same resolution may save nothing, especially when the original is only slightly over the target. The tool then lowers the resolution and tries again; if no attempt comes out smaller than the original, it keeps your original and says it is still over the target. Choosing 720p or 480p up front usually makes the difference.

iPhone HDR videos

iPhone 12 and later models record HDR video in Dolby Vision unless the option has been turned off. Re-encoding HDR footage as ordinary H.264 without any conversion can leave it looking grey and washed out on standard screens, because players still treat it as HDR. The compressor detects HDR video, has the browser convert every frame to standard colour (BT.709) and labels the file to match; the rotation of portrait clips is drawn into the picture at the same time.

The result is a standard-dynamic-range video, so highlights won't glow the way they do on an HDR display. If most of your clips end up on ordinary screens, HDR recording can be switched off under Settings › Camera › Record Video › HDR Video.

Size limits you'll run into

• Email: Gmail accepts up to 25 MB of attachments per message and turns anything bigger into a Google Drive link. Other services set their own caps, often 20 to 25 MB.
• Discord: in August 2026 Discord raised the free upload limit from 10 MB to 20 MB per file. Type 20 into Custom — or pick 10 MB if you're unsure which limit applies.
• Forms and portals: job applications, coursework systems and competition entries normally state a limit next to the upload button. That number is the one to use.

Limits change, so check the current figure before you compress. The target counts 1 MB as 1,000,000 bytes, the stricter reading, so a file that meets it also fits a limit that counts 1 MB as 1,048,576 bytes.

Photos have their own tool: the image compressor aims at a size in KB. If a video only needs to become an MP4 rather than a smaller file, MOV to MP4 rewraps it without touching the quality, and if only the sound matters, MP4 to MP3 keeps just the audio.

When a link beats compressing

If the person receiving the video needs full quality — an editor, a client, anything bound for a big screen — send a link instead. Gmail's Drive link, Mail Drop in Apple Mail (files up to 5 GB, available for 30 days) and any cloud-storage share deliver the original untouched. And compress from the original every time: putting an already-compressed video through a compressor again costs quality twice.

Frequently asked questions

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