Everything it does
Features
Every detail of how Cassette sounds, looks, and works, built for people who actually care about their music.
Real-Time Analysis
See every frequency,
the instant it sounds.
A 128-band spectrum analyzer driven by a 4096-sample FFT with Blackman-Harris windowing. The same math pro audio tools use. Buttery attack and release smoothing, redrawing at 165+ frames per second. Most players give you a toy. This is an instrument.
Watch the low end breathe, catch a harsh resonance in the mids, see exactly where a track lives in the spectrum. Whether you're EQ-matching a playlist, checking a master, or just mesmerised by your favourite record, it's all there in real time. Accurate, responsive, and genuinely beautiful.
Stereo Scope
See your stereo field
in real time.
A live goniometer plots every sample pair as a mid/side dot cloud, so you can see at a glance whether a track is mono-compatible, wide, or phase-reversed. The correlation bar below reads from −1 (total cancellation) to +1 (perfect mono). Catch problem mixes before they hit a mono speaker.
When the cloud collapses to a vertical line, you're listening to pure mono. When it fans sideways, the stereo image is breathing. Most players hide all of this. Cassette puts it right in front of you.
Waveform
See the track.
Scrub to the beat.
Every waveform is rendered with our own dual-layer peak & RMS analysis. The loud transients and the quiet body drawn separately, so the structure of the track reads at a glance. Intros, breakdowns, drops and outros become visually distinguishable before you ever press play.
Then grab it and go. Smooth, precise scrubbing straight off the waveform, and scroll to zoom right down to the individual sample. Find the exact beat every time. You'll see the drop coming before it hits.
Video Playback
Your whole collection.
Audio and video.
Music videos. Concert films. Live sets in 4K. Cassette plays it all natively, with multiple audio tracks and embedded or external subtitles you can switch on the fly. Commentary, dubs, alternate mixes, foreign-language subs, whatever the file carries.
One library for your whole collection. Audio and video side by side, organised the same way, played by the same engine. No second app, no juggling windows.
Plays virtually everything you'll throw at it
YouTube Playback
Paste a link.
Just play.
Found a live set, a rare B-side, or a mix on YouTube? Paste the link into Cassette and it streams the audio directly. No download, no browser tab, no ads interrupting your flow. It lands in your queue like any other track, with crossfade, EQ, and the spectrum analyzer all working as normal.
It's not just single videos either. Drop in a whole YouTube playlist and Cassette queues every track, or paste a SoundCloud link and stream that too. Add it to a playlist, let it crossfade into your library, treat it exactly like a file you own — because for the duration of that session, it is.
Mini Player
Always on top.
Out of the way.
Shrink Cassette into a compact always-on-top mini player that floats above your other windows. It works for both audio and video. Keep a track spinning while you work, or pin a music video to the corner of your screen.
Full transport controls, live progress, and artwork in a footprint small enough to forget it's there until you need it. Producers: pin a reference track in the mini player while you work in your DAW and A/B your mix against the real thing without ever losing focus.
BPM & Key Detection
Know your library, deeply.
BPM and Camelot key detection that runs 100% offline. Bundled analysis engines, zero internet, zero API fees, nothing leaving your machine. Right-click any track, analyze, done. Results are written straight into your library and stay there.
Build harmonic sets that flow, find the tracks that actually mix in key, and sort your collection by tempo for the right energy at the right moment. The kind of metadata DJs pay subscriptions for. Yours, computed locally, for free.
Your Library. Offline.
It's all yours.
Forever.
No accounts. No telemetry. No cloud. Cassette reads your local files and keeps everything in a blazing-fast local database with gapless playback and seamless crossfades, every single time. Your music doesn't disappear when a subscription lapses or a server goes dark.
Accent Colors
Paint it your color.
Fourteen hand-picked accents that recolor the entire interface in an instant. Waveform, spectrum, controls, highlights, all of it. From Acid Lime to Bright Teal, the whole app shifts to match your mood the moment you pick one.
And Much More
Everything else.
Gapless & Crossfade
Seamless transitions between tracks, every time.
Mono Fold-Down
Check mono compatibility with a single click.
Playlists
Build and organise your library exactly how you like it.
Automatic Playlists
Drop a folder and Cassette builds playlists from your directory structure, automatically.
Smart Search
Find anything in your collection instantly.
Media Key Support
Play, pause and skip from your keyboard or headset.
Lightning Import
Index huge libraries in seconds into a fast local database.
Discord Presence
Show what you're listening to in your Discord status.
Driver Selection
Pick the exact audio backend mpv uses to reach your device.
Output Selection
Send playback to any hardware output on your system.
Channel Selection
From mono to 7.1, request the speaker layout you want.
Sample Rate
Lock output to 44.1 kHz right up to 192 kHz, or auto.
Headphone Crossfeed
Blends left and right channels the way your ears naturally hear sound, reducing listening fatigue and makes stereo feel real on headphones.
Metadata Editing
Fix titles, artists, albums, track numbers, and artwork without leaving the app. Edit one track or batch-edit an entire album at once, with automatic artwork built right in — Cassette finds albums with no cover and fetches high-resolution art for you.
On the roadmap
Features we're working on.
Graphic Equalizer
A 10-band graphic EQ built directly into the player. Boost the low end, tame a harsh high-mid, carve out the perfect listening curve. Zero latency.
9D Music Effect
A spatial audio engine that wraps sound around your head in 360°. Transforms any stereo track into a fully three-dimensional experience.
Headphone Profiles
Save a custom EQ curve per device and switch automatically when you plug in. Ships with professionally tuned profiles for major headphone brands.
Own it from day one.
Cassette is in early access. Become a supporter and get a lifetime license now, at half of what it will cost at full release. Your activation key lands in your inbox right after checkout.
One payment. Yours forever. Prices exclude VAT.