Crop, don't resize, when content matters
Resizing is what you do when you need a specific aspect ratio and don't care which pixels survive. Cropping is what you do when specific pixels matter. If there's a webcam overlay in the corner of your screen recording, resizing won't remove it — it'll just shrink it. A crop cuts it out entirely. Same for sidebar UI you don't want, browser chrome at the top of a tab recording, or a logo watermark another tool baked in.
When to use each preset
Square (center) is for Instagram feed posts and product hero shots — it grabs the largest centered square that fits in your frame. Top / bottom half is for cleaning up screen recordings: top half usually grabs just the app window above the dock, bottom half is for grabbing chat transcripts or terminal output. Left / right half is rarer but useful for splitting a side-by-side comparison recording into two clips. For anything more precise, Custom with X / Y / W / H gives you pixel control.
How to figure out the crop coordinates
We don't ship a click-and-drag visual cropper — that adds enough complexity (canvas overlays, scrubber, frame seeking) that we'd need to build a real video editor. Instead: open the file in QuickTime, VLC, or your default player, hover the mouse over the top-left corner of the area you want to keep, note the coordinates, then do the same for the bottom-right. Subtract to get width and height. Plug them into Custom mode here. Five seconds slower than a visual tool, but it always works.
Cropping preserves audio losslessly
Because cropping only changes the visible pixel grid, we re-encode the video stream (CRF 22 H.264, visually transparent) but copy the audio track straight through with -c:a copy. There's no quality loss on the audio at all — it's byte-for-byte identical to the source. If you'd rather record content already framed correctly, Clipy's recorder lets you pick a specific window or region at capture time so cropping is unnecessary.