Compress a video online, on your device

A video's size comes down to simple arithmetic: its bitrate multiplied by its duration. The bitrate is how much data is spent on each second of picture and sound. A video at 8 megabits per second weighs 1 MB per second, which is 60 MB per minute.

Three settings push that bitrate up. Phones set them high by default to keep a flawless picture on a large screen, which is rarely needed for a video you send to a customer.

• Resolution: a 1080p frame holds 2.25 times as many pixels as a 720p frame, and a 4K frame four times as many as 1080p. Every extra pixel has to be described.
• Bitrate: at the same resolution, a higher bitrate keeps more detail in motion and texture. It is the setting that weighs most on the file.
• Duration: two minutes weigh twice as much as one. Trimming ten idle seconds off the start is the easiest saving there is.
• Frame rate: 60 frames per second needs more data than 30, often with no visible difference on a product or presentation video.

Each goal sets a resolution and a bitrate, and the tool shows the estimated size before you start. The limits quoted here were read on the services' own help pages on 2 October 2026. They can change: if in doubt, use "Target size" with the figure the service gives you.

• WhatsApp: the Help Center gives 64 MB as the maximum for a video sent in a chat, on all platforms, and adds that the default limit is 100 MB and 720p on a faster connection, 64 MB and 480p on a slower one. Sent as a "Document", a video can be up to 2 GB. The goal aims for 60 MB at most, in 720p. Source: faq.whatsapp.com/823886715479103.
• Email: Gmail caps attachments at 25 MB for personal accounts and replaces anything larger with a Google Drive link; Outlook.com also caps file attachments at 25 MB. An attachment grows by about 37% when it is Base64-encoded into the message (RFC 2045), so the goal aims for 17 MB at most. Sources: support.google.com/mail/answer/6584 and support.microsoft.com/en-us/outlook/sending-limits-in-outlook-com.
• Website: there is no common limit. The goal keeps a sharp picture, 1080p at most, at a moderate bitrate so the page loads quickly on a phone. If your host or site builder sets a maximum file size, use "Target size" instead.
• Maximum quality: the original resolution is kept at a high bitrate. Choose it for a video that will be edited or shown on a big screen afterwards. The saving is smaller.
• Target size: you type the size to stay under, in MB. The tool works out the bitrate from the duration, and lowers the resolution once that bitrate is too low for a clean picture.

Video compression throws away detail the eye barely notices. The lower the bitrate, the more visible the loss: fast motion smears, fine textures such as fabric or foliage flatten out, and blocks show up in dark areas and gradients. Small on-screen text gets harder to read.

Lowering the resolution works differently: the picture stays clean, but it is less sharp on a large screen. On a phone, 720p is still perfectly readable. That is why the tool would rather reduce the resolution than keep a large picture with too little data.

Two tips. Always start from the original file: compressing an already compressed video stacks the losses. And watch the result before you send it: the two players show the original and the compressed version, so you can judge for yourself.

Most online compressors begin by uploading your video to their servers. With a file of several hundred megabytes on a mobile connection, that upload is often the slowest step, and your video ends up with a third party. Here nothing is uploaded: your browser reads the file, your device's video encoder compresses it, and the result is handed straight back to you.

Speed therefore depends on your device. When it has a hardware encoder, the work goes quickly; on an entry-level phone, allow more time. The tool shows progress, the time left, and then how long it really took.

Encoding video is heavy computing: the device warms up a little and the battery drains faster than usual. For a long video, plug the phone in and keep the page on screen, because browsers slow down tabs in the background.

The video is never loaded into memory as a whole. It is read in pieces, and the result is written as it goes to temporary storage inside the browser, which is cleared when you start over or leave the tool, or on your next visit at the latest. Details the phone stored in the file, such as the place, the date and the device model, are not copied over.

The tool reads MP4, MOV, WebM and MKV files, provided the browser can decode the video inside. H.264, the most common codec, is read everywhere. When a file cannot be decoded, the tool says so as soon as you add it rather than failing halfway through.

The result is an MP4 with H.264 video and AAC sound, the pair that almost every phone, computer and app can play. If your browser cannot encode those formats, the tool writes a WebM (VP9 and Opus) and tells you why before you start.

Encoding relies on a recent browser feature, WebCodecs. According to MDN's compatibility data, checked on 2 October 2026, these are the versions that provide it.

• Chrome and Edge on desktop: from version 94. Chrome for Android: supported in its current version.
• Safari on Mac, iPhone and iPad: from version 16.4 for video, and from version 26 for sound. In between, the tool copies the original sound across when it is AAC; otherwise it warns you that the video will have no sound.
• Firefox on desktop: from version 130. Firefox for Android does not offer the feature yet.
• A browser that is too old: the tool shows a clear message and does not read your file.