WhatsApp's limits
WhatsApp has long limited videos sent as media to 16 MB, and many guides still give that figure; newer versions are reported to accept larger videos on some platforms. Anything up to 2 GB can be sent as a document, but then it does not play in the chat. Because WhatsApp's help pages could not be checked automatically, these figures are marked unverified in the sources below. The 15 MB target here works on every version of WhatsApp and still previews in the chat.
What this preset does
It targets 15 MB, keeps the resolution at 720p or below (WhatsApp shows videos at phone size, so higher resolutions waste the limit), keeps the sound, and encodes MP4 with H.264 and AAC, which every phone plays. If the result comes out over the target, it re-encodes at a corrected bitrate.
Sending it
- Download the compressed video.
- On a computer, attach it in WhatsApp Web or desktop using Photos & videos. On a phone, save it to your gallery and attach it from there.
- If WhatsApp still offers to send it as a document, the file is over that version's limit: choose a custom size of 12 MB and try again.
Long videos
Beyond about 3 minutes, 15 MB means a soft picture. Trim the video to the part that matters, split it into parts with the trim tool, or send a link from cloud storage.
What decides a video's file size
A video file is mostly its bitrate (how many bits are spent per second) multiplied by its duration. A 2-minute clip at 2 megabits per second is about 2 × 120 ÷ 8 = 30 MB, plus the sound. Everything else matters only through the bitrate it needs to look good:
- Resolution. 1080p has 2.25 times the pixels of 720p, so it needs roughly twice the bitrate for the same sharpness. Below a certain bitrate, a smaller resolution looks better than a blocky big one, which is why the automatic setting steps down.
- Frame rate. 60 fps needs more bitrate than 30 fps; for talking, screen recordings and most phone clips, 30 or even 24 fps is plenty.
- Movement and detail. A static screen recording compresses far better than handheld footage of a crowd, confetti or water. Two videos of the same length and settings can differ several-fold in size.
- Codec. H.264 plays everywhere. VP9, HEVC (H.265) and AV1 give the same quality in 30 to 50% fewer bits but are not supported by every player or upload form.
- Sound. Usually small: 96 kbps stereo is about 0.7 MB a minute. Removing it helps only for very small targets.
If WhatsApp refuses or blurs it
- Check the result is under 16 MB; if WhatsApp still converts it to a document, choose a custom size of 12 MB.
- WhatsApp applies its own compression to media. To keep more quality, enable "HD" when sending on recent versions of the app, or send the original as a document.
- On a computer, WhatsApp Web and the desktop app send the same way as the phone.
Portrait phone videos
Vertical videos are handled the same way: the resolution limit applies to the shorter side, so a portrait 1080×1920 video becomes 720×1280 at most.
Privacy
Your video never leaves your device. It is read and written in the browser tab; there is no upload, no server-side processing and no account. You can disconnect from the internet after the page has loaded and it still works. Free use has no watermark and covers files up to 500 MB and 10 minutes; the A$9 lifetime licence removes those limits (your device's memory still applies), queues up to 20 files and saves presets.