Free video compressor that never uploads your file

Most sites that rank for “video compressor” want you to upload your file, wait in a queue and pay to lose the watermark. This one runs in your browser: you can compress video without sending it anywhere, and you see the estimated size before you click a thing.

How to compress a video in 4 steps

1. Drop in your video

   Done

   MP4, MOV, WebM or MKV, from your phone or computer. The video engine downloads at that moment, not when the page opens.

2. Pick your goal

   Done

   “Quality” if you want it lighter and still sharp; “Max file size” if you have a hard cap, like an email attachment. The estimated size updates instantly with every option.

3. Set resolution and audio

   Done

   Going from 1080p to 720p removes more than half the pixels and is hard to spot on a phone. Need to remove audio from video, like copyrighted music? Tick “Remove audio”.

4. Compress and download

   Done

   You’ll see progress and time left. When it’s done, check the result in the player and download the MP4.

Whether you need to compress video for email, compress video for discord or just reduce video size before posting, the recipe is the same: a max size or “Balanced”, 720p, done. Got dead air at the start or end? Cut it first with the video trimmer: fewer seconds is the cheapest way to save megabytes.

How the size estimate works: bitrate times duration

A video’s file size is almost exactly its bitrate multiplied by its length. The tool calculates it like this:

• Estimated size (MB) = (video bitrate + audio bitrate) × seconds ÷ 8,000,000
• In “Quality” mode, the bitrate comes from pixels per second: width × height × frames × a factor (0.1 for High, 0.065 for Balanced, 0.04 for Smallest file), never above the original’s bitrate.
• In “Max file size” mode, it runs the math backwards with a 6% safety margin. If the encoder still overshoots, it makes one more pass with an adjusted bitrate so you never go over.

That’s how to compress a video without trial and error.

Compress video online without uploading it

Almost every tool that lets you compress video online uploads your file, processes it on a server and sends it back. Here your own browser does the work with WebCodecs, the built-in video encoding API in Chrome, Edge, Firefox and Safari, plus Mediabunny, an open-source library that reads the file and builds the MP4. No size cap, no queue.

The output is H.264 inside an MP4, the format WhatsApp, Instagram, LinkedIn and email clients all accept. So this free video compressor gives you the same compatible MP4 whether you start from MP4, MOV or WebM.

HandBrake compress video: best settings and when to skip it

HandBrake is free, open source and still the standard for desktop work. Its own documentation suggests a constant quality (RF) of 20 to 24 for 1080p and 22 to 28 for 4K, and says a lower number means higher quality. The catch: RF picks quality, not file size. You encode, check the result and run it again until it fits.

Pick HandBrake for H.265, batches or two-pass encodes. Pick this tool when:

• You have a hard cap in MB, like an email attachment or an upload form.
• You want the estimated size before you start.
• You are on a locked-down work laptop or a phone, where you can’t install anything.

Compress video on iPhone: free, in Safari, no app

Per Apple’s help page, HEVC, the high-efficiency format iPhones use by default, compresses better than H.264, the one behind “Most Compatible” mode. This tool outputs H.264 in an MP4, so the settings matter:

1. Open the page in Safari 17 or later and pick the video from Photos.
2. Got an upload cap? Use “Max file size.” If not, go “Balanced” at 720p.
3. Shooting in 4K? Drop to 1080p or 720p, because that is where most of the savings are.
4. Download the MP4. Safari saves it to the Files app, in Downloads, and the Share menu sends it back to Photos.

One more thing: to look the same, H.264 needs more data than HEVC. An iPhone clip will shrink less on “High” than footage from a camera that records H.264, so lower the resolution to make up for it.

Frequently asked questions about compressing videos

01

How much can a video compressor reduce file size?

It depends on what you start with. Phone footage is recorded at a high bitrate, so it usually shrinks by 50 to 80% with no visible change on a phone screen. Drop from 1080p to 720p and you cut the pixel count by more than half, so 85 to 90% savings are common. A video that’s already been compressed, like a download from social media, has far less room to shrink.

02

What are the limitations of using a video compressor?

Every compressor throws away data, so pushing too hard shows up as blocky shadows and smeared detail. Online tools add their own limits: upload caps, queues, watermarks and the privacy question of sending your file to a stranger’s server. This one runs locally, so the only real limits are your device’s memory and a modern browser with WebCodecs.

03

How do I compress a video for Discord?

Pick “Max file size” and type a number just under your upload cap. Discord’s help page listed 20 MB for free accounts in October 2026, up from the old 10 MB, so 19 MB leaves a safe margin. For clips longer than a minute, switch to 720p too, so the bitrate doesn’t drop so low that the video looks rough.

04

How do you compress a video?

You re-encode it with fewer bits per second. The codec, usually H.264, stores a full picture every few seconds and only the changes in between. Lower the bitrate and every frame takes less space while fine detail gets simplified. This tool does exactly that in your browser with WebCodecs, then saves the result as an MP4.

05

How do I compress a video for email?

Choose “Max file size” and set 25 MB, the attachment limit for personal Gmail accounts; anything bigger gets swapped for a Google Drive link. Other providers and many work accounts set their own caps, so when in doubt, aim a little lower. Long video? Drop to 720p first so it still looks sharp at that size.

06

How do I compress a video to 10 MB?

Choose “Max file size,” tap 10 MB and the tool sets the bitrate for you, keeping about 6% of margin. How much video fits depends on length and resolution. At 30 fps, the tool stays quiet up to roughly 45 seconds at 1080p, 90 seconds at 720p and nearly 3 minutes at 480p. Those figures are our own calculation from its warning threshold, with 128 kbps audio. Past them, it warns you that quality will suffer, and the fix is a lower resolution or a shorter clip.