How to Compress a Video for WhatsApp, Email or Upload Limits
Phone cameras record beautiful, detailed video, and huge files to match. A two-minute 4K clip can be close to a gigabyte, far too much for an email, a form upload or a chat app on a slow connection. Compressing it well means making it small enough to send while keeping it pleasant to watch.
What decides a video's size?
Video size comes down to two numbers: bitrate (how much data per second) and length.
Size ≈ bitrate × duration
Resolution and frame rate matter because higher resolutions need a higher bitrate to look good. A 4K video at 60 frames per second needs far more data than a 720p video at 30. To make a video smaller you can:
- Make it shorter.
- Lower the bitrate (quality).
- Lower the resolution, so a lower bitrate still looks clean.
Step 1: Cut what you don't need
The cheapest megabytes to save are the ones nobody wanted to watch. Fumbling at the start, the phone going back into your pocket at the end: remove them with Trim Video. In fast mode, trimming copies the video without re-encoding, so it's quick and lossless.
Step 2: Compress to a quality or a size
Open the Video Compressor and add your MP4, MOV or WebM video. You have two approaches:
- Pick a quality when you just want it smaller and don't have a strict limit.
- Pick a target size in MB when a platform or form has a limit. The compressor aims slightly below your target. If the first result is still too big, it compresses again and, if needed, reduces the resolution, and tells you when it does. A target that's far too small for the video's length is refused, with the smallest size that works.
There's no watermark, and the progress bar shows the time left. Most phones and laptops compress a one-minute 1080p clip in under a minute.
Step 3: Choose a sensible resolution
Most people watch shared videos on a phone. For that:
- 1080p looks sharp on any phone and is a good default.
- 720p is plenty for chat apps and saves a lot of space.
- 4K only makes sense if people will watch on a large screen and the file size doesn't matter.
Lowering the resolution often improves the look at small sizes, because the available data is spread over fewer pixels.
Plan with the bitrate calculator
Want to know in advance what a size limit means for quality? The Bitrate Calculator works out the bitrate that fits a file size, including audio and overhead. For example, to fit 10 minutes into 1 GB, you need about 13 Mbps in total. If the bitrate it gives is very low for your resolution, lower the resolution or shorten the video.
Sharing tips
- Chat apps often compress videos again when you send them as media. Sending as a document or file (where the app allows it) keeps your version intact.
- Email attachments are commonly limited to around 20–25 MB. For longer videos, compress hard or share a link from your cloud storage.
- Upload forms state their limits near the upload button. Aim a little below them.
Common questions
Why does my compressed video look blocky? The bitrate is too low for its resolution or for fast motion. Choose a lower resolution or a slightly larger target size.
Does compressing remove the sound? No. Audio is kept; it's a small part of the size.
Can I compress several videos at once? Compress them one after another. Each one runs on your device, so speed depends on your computer or phone.
Your videos never leave your device
Family videos, work recordings and anything you'd rather not share with a stranger's server stay private: compression runs in your browser, and nothing is uploaded.