2Enter the start and end time of the part you want to keep.
3Preview the selection and run the cut — the part you keep is copied through untouched wherever the format allows it.
4Download the trimmed Opus file.
Opus Cutter FAQ
Does the format limit where I can cut?
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It does. Opus is the best-in-class lossy codec at low bitrates and the standard for voice and real-time audio. That is precisely what decides whether a cut can be placed arbitrarily or has to land on a structural boundary.
Anything specific to Opus when trimming?
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Yes — Opus always resamples to 48 kHz internally, so sample-rate choices you make elsewhere in the chain do not survive into it. It explains most of the "the cut is a fraction of a second off" surprises.
How does Opus Cutter cut the file?
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Concretely, the cut is made on frame boundaries and the surviving frames are copied through without re-encoding, so the audio you keep is bit-identical to the original — no second generation, and the job finishes in about the time it takes to upload. You set the start and end points on the waveform or the timeline and keep what is between them.
What can I upload to Opus Cutter?
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MP3, AAC, M4A, OGG, Opus and WMA are the lossy codecs handled directly, and lossless sources (WAV, FLAC, AIFF) can go in the same batch. The codec is probed from the stream, so an incorrectly named file still works.
Is there a file size limit on Opus Cutter?
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Yes: free accounts process audio up to 15 MB per file, which at typical bitrates is several hours of material; ffmpeg does the decoding and encoding, exactly as it would on a desktop. That is the most generous cap on the site after video, and audio work rarely runs into it.
Why would a modern-format site run Opus Cutter?
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WEBP.to is built around the modern replacement for both of the old defaults: one format that does lossy, lossless, alpha and animation, and reliably lands smaller than the JPEG or PNG it came from. People arrive here having decided the old defaults are costing them bandwidth, and that decision immediately raises the rest: what size, what quality, what happens to the transparency. Opus Cutter is on the same upload and the same account so those questions get answered in one place.
Once Opus Cutter has run, what is worth doing next?
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The converter on this site moves images to and from WebP, PNG, JPG and AVIF, which is where you decide whether a smaller file is worth losing the older browsers. Doing it in that order matters: pick the pixels first and the container afterwards, because the container is the cheap decision and the pixels are the expensive one.
Do the sibling sites run something different?
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The engines are identical — same libraries, same workers, same caps. What is different is the opinion attached, and the opinion here rests on a property of the format this site is named after: the same .webp extension can hold a lossy VP8 frame, a lossless one, or an animation, so the sensible processing path is decided per file rather than per extension.
What happens to my file, and is an account required?
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No account is needed. Uploads and results are kept for about 24 hours, which leaves time to download the result, and are then deleted automatically; nobody reads, lists or indexes them. Several files in one job need a paid plan.
