Set the limit in MB and the video is shrunk until it fits, right in your browser. Nothing is uploaded to any server.
Most compressors ask you to guess a "quality" and find out the size afterwards. Here it is the other way around: you pick the WhatsApp, Discord or email limit (or type a value in MB) and the tool works out the bitrate that fits. The math is size = (video bitrate + audio bitrate) x duration / 8, minus about 3% of headroom and the container's own weight. A 60-second video squeezed into 16 MB, for example, allows roughly 2.1 Mbps in total. With that bitrate the tool picks the resolution from the bits per pixel of each frame: 720p at 30 fps needs about 1.7 Mbps (0.06 bits per pixel) to look good in H.264, while a 5-minute video in the same 16 MB drops to 360p, because 720p would turn into blocks. Audio adapts too: 128 kbps when there is room, 64 kbps or less (in mono) when the limit is tight. After encoding, the real file is measured. If it overshot, the bitrate is recomputed from the measured ratio and the video is encoded again, up to four times. If the target is impossible, the tool tells you the smallest workable size instead of handing over an unwatchable file: 60 minutes into 8 MB, for instance, would leave under 18 kbps for everything. Encoding uses the browser's WebCodecs API, in H.264 (MP4) when available, or VP9 (WebM) when not. The video never leaves your device.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/video-compressor"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Video Compressor (WhatsApp, Discord, email)"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
Pick the limit you want to hit and click Compress. WhatsApp's Help Center lists 100 MB for chat videos on fast connections (720p) and 64 MB on slow ones (480p); the classic 16 MB limit is still the most quoted and the only one safe on every version. Check yours: the targets here are editable. Tip: WhatsApp usually recompresses videos sent as media. Sent as a document, the file stays original, up to 2 GB.
Compression runs in your browser. The video is not sent to any server.