How to compress a large video file for free, down to a size you choose

Why large videos are so large

A video file's size comes almost entirely from its bitrate, the number of bits spent on each second of picture, multiplied by how long it runs. Phones, action cameras and screen recorders use generous bitrates because they have to encode in real time, so a ten-minute clip can easily reach several gigabytes. A 4K recording from a recent phone can use hundreds of megabytes per minute.

That generosity is the opportunity. A compressor has time to think, so re-encoding the same footage at a much lower bitrate often looks the same at normal viewing size. The size drops from gigabytes to tens or hundreds of megabytes. For the full theory, see how to compress a video without losing visible quality. This page is about the practical side of large files and fixed limits. Screen recordings are a classic oversized file, and recording your screen with sound covers getting a clean one in the first place.

Compress a big video in your browser, step by step

The video compressor reads the file straight from your disk. Nothing is uploaded, so a 10 GB file does not sit in an upload queue first, and there is no site-imposed size cap. Encoding uses your graphics hardware where the browser allows it, so most videos finish faster than real time.

1. Open the compressor and choose your video, or drop it on the page. It accepts MP4, MOV, M4V, WebM and MKV.
2. Pick a quality preset, High quality, Balanced or Smallest file, or switch to Exact file size and type a number of megabytes.
3. Optionally lower the resolution or frame rate. The estimated size updates as you change them.
4. Compress, watch the preview on the page, then download the new file.

Honest note about very big files: the work happens in your computer's memory. A multi-gigabyte file is fine on a laptop or desktop with enough free memory, but a phone or an older machine may struggle. If it does, trim the video first so there is less to process.

Compress a video to a certain size

Most people who search for a way to compress a video to 50 MB, 10 MB or even 4 MB have a hard limit: an email attachment, a form upload, a chat app. In Exact file size mode you type the limit and the compressor works backwards. It divides your size budget by the video's length to get a bitrate, keeps a small share for the audio and the file wrapper, and aims just under your number.

Encoders do not always land perfectly. If the first attempt comes out even a little too big, the compressor runs a second pass with a corrected bitrate, so you do not have to guess and retry.

The limit that matters is length. A target size only works if the maths leaves enough bits for a watchable picture, and you can check that yourself with the bitrate calculator. It turns size and length into bitrate in both directions. As a rough guide, a 10 MB target for a 10-minute video leaves about 130 kilobits per second in total, which is not enough for a clean picture at any resolution. For the same 10 MB, a 30-second clip has about 2.7 megabits per second, which looks fine at 720p.

The levers, in order of impact

Resolution

This is usually the biggest single change. Each step down, 4K to 1080p or 1080p to 720p, cuts the number of pixels to describe by more than half. If a 4K file is far too large and will be watched on a phone or in a chat window, going down to 1080p or 720p saves the most space for the least visible loss.

Frame rate

Halving 60 fps to 30 fps removes half the frames. Tutorials, talks and screen recordings look identical at 30 fps. Keep 60 for gameplay and sport.

Bitrate or preset

Once the size of the frame is right, the preset sets how much detail survives. If the video is a static talking head, Balanced is plenty. Fast motion and grain need more.

Codec

Under Format and codec you can choose the encoder. H.264 in MP4 plays everywhere and is the safe default. H.265 (HEVC) and AV1 make noticeably smaller files at the same quality, but older devices may not play them. VP9 in WebM suits websites. Options your browser cannot encode are greyed out. If you are not sure what the original uses, Video Info shows its codec and bitrate.

Making a huge file smaller before you compress

The cheapest bytes to remove are the ones nobody needs. Use the video trimmer to cut the start, the end and any dead sections. A 40-minute recording with 15 useful minutes becomes less than half the size before any compression happens, and the compressor then has less to chew through.

If the sound is the part you need, you do not have to keep the picture at all. Extract Audio saves the soundtrack on its own, which is tiny in comparison. The steps are in extracting audio from a video.

When compression will not help much

Videos you downloaded from a social platform have usually been compressed hard already. Squeezing them again barely reduces the size and costs quality, and the compressor says so rather than giving you a file that is only slightly smaller.

Very long videos with a very small size target will also look rough. When that happens, you have three honest choices: accept a lower resolution such as 480p, which looks far cleaner than a smeared 1080p, cut the video shorter, or raise the limit if you can, for example by sharing a link instead of an attachment.

Compression is also permanent. Keep the original if you might need the full quality later, and treat the compressed file as the copy you send.

Large file or a format problem?

Sometimes a file is large because of the format, not the content. An uncompressed or lightly compressed recording is far bigger than an H.264 MP4 of the same footage. Converting to MP4 with the video converter can help, but the compressor is the better first stop because it lets you set the size directly. The longer explanation is in converting video formats for free.