Video Compressor

Why I built another video compressor

Most of the video compressors I tried do one of two annoying things. They stamp a logo on the result unless you pay, or they give you a slider labelled "smaller" and "better" and leave you to guess. You move it, wait, download, and the file is 31 MB when the email limit is 25. So you go again.

This one has a target size mode. You type 25, it works out the bitrate from the length of your clip, runs a two-pass encode, and the file comes back at or just under 25 MB. It's the same method people use with FFmpeg on the command line, minus the command line. There's no watermark on anything, ever.

The two ways to compress

Quality preset

Use this when you don't have a specific limit and just want the file to stop eating your phone storage or upload faster. There are three levels:

• High quality keeps detail you'd notice on a big screen. A 4K phone clip still shrinks a fair bit because phones record at very high bitrates.
• Balanced is the default and the one I'd pick for most things. Phone videos usually come out somewhere between a third and a fifth of the original size.
• Smallest file pushes harder and caps the picture at 720p. Fine for a group chat, not for something you want to keep forever.

Target file size

Use this when a service will reject anything over a number. Type the number, or tap one of the shortcuts. The first pass reads the whole video to see where the hard parts are (fast motion, confetti, water). The second pass spends the bitrate where it's needed, so the quiet parts don't waste bytes and the busy parts don't fall apart.

If the target is too small for the length of the clip, you get a message that says the smallest size that will still look like video, instead of a mushy file. A 10 minute clip simply can't fit in 2 MB.

Size limits you probably ran into

Sending a video and a document in the same email? compress the PDF too, so the two together stay under the limit.

• Gmail and Outlook: about 25 MB per email, attachments included. Aim for 24 to leave a little room.
• Discord: 10 MB for free accounts. Nitro raises it, but the person you're sending to doesn't care.
• WhatsApp: large files can go as documents, but videos sent as media get recompressed hard. Sending a 16 MB file you've already compressed well usually looks better than letting WhatsApp do it.
• Job portals, school systems and forms: often 20 MB, 50 MB or 100 MB. Check the small print next to the upload button.

Real situations where this helps

A teacher records a 6 minute lesson on an iPhone. The MOV is 480 MB because the phone shot it in 4K at 60 frames a second. The school portal takes 100 MB. Target size 95 MB, Automatic resolution, and it comes back as a 1080p MP4 that plays in every browser.

Someone wants to post a 40 second clip from a game in a Discord channel. OBS saved it as an MKV at 70 MB. Target 10 MB gives an MP4 that Discord previews inline, which an MKV never does.

A small business owner has a product video for a marketplace listing that caps uploads at 50 MB. The editor exported 210 MB. Balanced preset gets it to around 40 MB and nobody watching on a phone will see the difference.

And a support agent needs to send a customer a 3 minute screen recording showing where a setting lives. Screen recordings barely move, so even the High quality preset usually cuts them down to a few MB, small enough to attach to a ticket without a second thought.

What happens to your video

Got a WebM screen recording where only the voice matters? The WebM to MP3 converter pulls the narration out as a small audio file.

The upload goes to our server over HTTPS and is processed by FFmpeg with the x264 encoder. The original file is deleted as soon as compression finishes, or straight away if it fails. The compressed copy sits in a download folder that's cleared automatically within about 10 to 25 minutes. Nobody looks at the files and nothing is kept for training or anything else.

The output is always MP4 with H.264 video and AAC audio. That's not the smallest possible format, but it plays everywhere: iPhones, Android, Windows, Macs, smart TVs, every browser, every chat app. A slightly smaller HEVC or AV1 file isn't much use if the person you send it to can't open it.

Limits worth knowing

• Files up to 100 MB per upload and videos up to 30 minutes long.
• Only the first video track and the first audio track are kept. Extra audio languages and subtitle tracks are dropped.
• Audio is converted to stereo AAC. A 5.1 movie soundtrack will be downmixed.
• HDR footage from newer phones is converted to standard 8-bit colour so it plays on everything. It may look a touch less punchy on an HDR screen.
• Big files take time. A long 1080p clip in target size mode is encoded twice, so give it a few minutes.

Getting the best result

For lectures, interviews and music videos, you can extract the audio as an MP3 with our MP4 to MP3 converter and skip the video altogether.

Start from the original file, not one that's already been through WhatsApp or a social app. Every round of compression loses a bit more, and squeezing an already squeezed video mostly just makes it uglier.

Trim first if you can. Cutting 30 seconds of dead air from the start of a screen recording does more for the file size than any setting here. Screen recordings and slideshows compress extremely well anyway, since most of the picture doesn't move.

If the result says it isn't smaller, the original was already efficiently encoded. That happens with videos exported from editing apps at sensible settings. Switch to Smallest file or set a target size, and it'll make the cut you asked for.

And if you only need the sound from a video, say a talk or a song, don't compress the video at all. Pulling the audio out gives you a file that's a tiny fraction of the size.