Crop any video to 9:16, 1:1, 4:5 or 16:9 for whatever platform needs it — Instagram, Reels, Shorts, TikTok or landscape. On-device, no upload, no watermark.
Instagram's feed has two viable shapes for video: the classic 1:1 square (still the safe default for grid composition) and 4:5 portrait, which takes up more screen real estate without cutting off in the feed. A 16:9 landscape clip dropped into either format gets letterboxed with dark bars top and bottom unless you crop it first — and a properly cropped video looks far more native in the feed.
Pick 1:1 or 4:5 above; Zimblu will crop your video's centre to that shape and export at full source resolution. A 1080p source becomes a 1080×1080 square or an 864×1080 portrait, both ideal for Instagram's recommended dimensions. Audio is copied untouched.
Reels, YouTube Shorts and TikTok all use the same 9:16 vertical canvas — the natural shape of a phone held upright. Most footage that goes viral on those platforms was either shot vertically to begin with or cropped from landscape into the centre 9:16 strip. The 9:16 preset above does exactly that crop, taking the central portion of your video.
From a 1920×1080 source the result is 608×1080 — full-height vertical, sized correctly for the platforms' recommended resolution. No watermark, no upload, no quality-throttled "free tier"; the tool delivers the result directly to your downloads. If the most interesting action isn't centred, the Zimblu app lets you slide the crop region to follow it — automatic subject tracking is a bigger job than a browser tool reliably handles.
Cropping a vertical clip to landscape is unusual but useful — for example, embedding a phone recording into a 16:9 video edit. The 16:9 preset takes the central horizontal slice of a vertical source, which usually contains the subject. Source pixels outside that slice are discarded.
Four presets cover the platforms most people crop for: 9:16 for Reels, YouTube Shorts and TikTok; 1:1 for Instagram's classic square; 4:5 for Instagram's portrait feed posts; and 16:9 for landscape. Each preset crops the centre of the picture to that shape.
They're discarded — the output contains only the cropped region. That's the whole point of cropping rather than adding letterbox bars: the result is the size you actually want, with no wasted pixels around it.
Yes — cropping changes the size of every frame, which means re-encoding the video stream once. Zimblu does this in a single decode-and-re-encode pass at a bitrate matched to the new (smaller) resolution. In our tests a 30-second 1080p clip crops to 9:16 in about 5 seconds — significantly faster than the original's length because the cropped resolution is smaller.
Audio is copied across untouched, byte-for-byte — cropping doesn't affect the audio at all. Same codec, same bitrate, same quality.
No. The whole crop happens inside your browser, on your own device. The file does not reach a server at any point. You can disconnect from the internet after the page loads and the tool keeps working.