Why this is fast
Native server ffmpeg outpaces browser WebAssembly by roughly 4–8x on identical hardware because it uses real SIMD, multi-threading, and direct disk I/O instead of the WASM shim. Uploads land at the nearest Backblaze B2 point of presence via a presigned URL, so a viewer in Paris is not pushing bytes through a single US-east origin. The cut runs server-side, the result comes back through Bunny CDN from the same edge. Most cuts on a few-minute screen recording finish in under five seconds end to end.
What this tool does, exactly
We seek with -ss and -to at the timestamps you typed and re-encode the kept section with libx264 at the veryfast preset, CRF 20, audio AAC 160 kbps, with -movflags +faststart and -pix_fmt yuv420p for maximum playback compatibility. Re-encoding gives you a frame-exact edge at the cost of a few seconds of CPU work, which is the right trade for a single-section cutter — lossless stream-copy snaps to keyframes and that snap is usually what users complain about.
When to reach for the multi-range trimmer instead
This page is the single-cut path: one start, one end, one clip out. If you need to keep several non-contiguous ranges from the same recording in one export — pull out minutes 2–3, 7–8, and 14–15 into one stitched MP4 — use the multi-range trim tool instead. It is built for that. The video cutter on this page is deliberately the fast, one-knob version.
Sister tools
Cut clip too big to share? Video compressor gets it under email and Slack limits. Need to change the speed? Video speed controller handles 0.25x to 4x with pitch-correct audio. Stitch two cuts together? Merge videos. Turn the cut clip into a short loop? MP4 to GIF. Grab a thumbnail from inside the cut? Video thumbnail maker. Recording the segment in the first place is even cleaner — Clipy records only the window you point it at, no trim step.