Tape Desk

Cut audio without handing it to a website

The "free online audio cutter" and "ringtone maker" sites are some of the ad-heaviest, upload-hungriest corners of the web — and the clip you're cutting is often a private voice memo or a recording you don't own the rights to reshare. Tape Desk does the whole job on your device: it decodes the file with your browser's own audio engine, and the trimming, splicing, fading, and WAV encoding all run locally.

What it does

• Trim: drag the two handles to select a region, preview it, and keep only that part.
• Join: load several clips, order them by dragging, and splice each one's selection end to end into a single track (mixed to a common sample rate and channel count).
• Ringtone: one button sets a 30-second selection — the classic iPhone/Android ringtone length.
• Fades & volume: optional fade-in/out on the edges and a gain slider.

Advanced mode — a small Audacity

Flip the switch at the top of the desk and every clip lands on one timeline. Drag on the waveform to select (across clips if you like), scroll the wheel to zoom, drag the ruler to pan, double-click a clip to select it. Then: split at the cursor, cut / copy / paste, delete, trim, insert silence, set a crossfade on the joins, and record straight from the microphone onto the end. Every edit is undoable. Effects apply to the selection — or to everything when nothing is selected:

• Level: normalize, amplify, fade in / out, compressor (with automatic make-up gain).
• Clean-up: noise reduction — select a stretch of pure hiss or room tone, take a profile, then apply to the whole thing; truncate silence to tighten up long pauses; low-pass, high-pass, bass & treble.
• Time: change speed (pitch follows), change tempo without changing pitch, or change pitch without changing length.
• Odds and ends: reverse, invert, silence.

Shortcuts follow Audacity where they make sense: Space play/stop, Ctrl+I split, Ctrl+X/C/V, Delete, Ctrl+T trim, Ctrl+L silence, Ctrl+A select all, Ctrl+E zoom to selection, Ctrl+F fit, Ctrl+Z / Y undo / redo, ← → nudge the cursor (with Shift for whole seconds). It's deliberately the useful fifth of Audacity — no plug-ins, no multitrack mixing, no spectrogram — and the whole thing is still one file.

Honest limitations

• Export WAV (lossless, universal — every phone and editor accepts it) or an MP3 at 128, 192, or 320 kbps when you want a smaller file to send. The MP3 encoder (LAME) is inlined so it still works fully offline; note that re-compressing already-lossy audio loses a little more quality, so reach for MP3 when size matters and WAV when it doesn't.
• Load an audio file or a video — Tape Desk pulls the audio track straight out of an MP4, MOV, or WebM and drops the video, so you can trim the sound out of a clip. Which formats open depends on your browser's built-in codecs; MP3, M4A/AAC, OGG, WAV, and MP4/MOV/WebM audio work in every modern browser, and exotic formats may not.
• WAV files are large (about 10 MB per stereo minute) — fine for ringtones and clips, heavy for a whole album.

Same shelf: File Mill converts the WAV to MP3 and back · Photo Cleaner and The Redactor do for images what this does for sound — local, private edits.

Part of K-Engine Local Tools — free, privacy-respecting utilities that run on your device. The waveform view, trim/join/fade, and WAV encoder are hand-written; view-source and you're reading them. MIT licensed, from the K-Engine workshop · download the source.