Guides / How to compress a video for email on Mac (under 20 MB)

How to compress a video for email on Mac (under 20 MB)

Updated 2026-07-10 · Runs locally — nothing uploaded

Quick answer

Choose the Email attachment ≤ 20 MB preset; FFmix calculates a practical bitrate, caps the video at 720p and compresses it locally on your Mac.

Output: Email-ready MP4 ≤ 20 MB
Processing: On your Mac
Setup: About 2 minutes to set up
Access: Free local task

Email is unforgiving: a video can look small in Finder and still be rejected once the message adds attachment overhead. FFmix’s Email attachment ≤ 20 MB preset keeps a safety margin instead of aiming at the provider’s last byte. It creates a compatible H.264 MP4, caps oversized footage at 720p and spends the available bitrate across the whole clip.

The file never takes an upload-and-download detour. FFmix runs the command on your Mac, shows it before execution and writes a new -compressed.mp4 next to the original. If the clip is unusually long, set a slightly larger target or trim unused footage rather than forcing every frame into too little data.

Steps

1 Drop the video into FFmix and choose Compress video.
2 Pick the Email attachment ≤ 20 MB preset, or enter your own target size.
3 Review the 720p, H.264 and audio settings plus the exact command.
4 Confirm; FFmix saves a new MP4 beside the source and leaves the original untouched.

Advanced: canonical ffmpeg recipe

This is the canonical recipe. FFmix adapts encoder flags to the engine on your Mac, then shows the final command; the command shown is the command run.

ffmpeg -i "input.mov" -vf scale=-2:720 -c:v libx264 -b:v 1100k -pass 2 -c:a aac -b:a 96k "input-compressed.mp4"

FFmix has a one-click "Email attachment ≤ 20 MB" preset

Drop a file and go — all local, nothing uploaded.

Download FFmix free

FAQ

Why does the preset target 20 MB rather than the full email limit?

Attachment limits vary, and MIME encoding adds overhead. A 20 MB target leaves practical headroom for providers that cap messages around 25 MB.

Can I email a long video at 20 MB without losing quality?

Every size target is a trade-off. For a long clip, trim dead time first or accept a lower resolution; FFmix shows the bitrate before you confirm.

Does the video get uploaded while it is compressed?

No. The bundled ffmpeg engine processes the file on your Mac, and the output stays beside the source.

Screen recordings are huge but compress well. Shrink yours on your Mac while keeping UI text sharp — no command line, nothing uploaded.

How to compress a video for Discord (under 10MB, free)

Discord's free upload limit is 10MB. Shrink any clip to fit on your Mac — no Nitro, no upload to a website. One click with FFmix.

How to reduce video file size on Mac without losing quality

Cut a video's size by roughly half at the same visual quality using H.265 — on your Mac, no command line, nothing uploaded. FFmix does it in one step.