Drag the speed down, open up the room, hear it immediately. Everything happens in this tab — your file is never uploaded and you do not need an account.
What it does
Slowed and reverb is a specific sound, not just a slow song. Two things happen at once: the track is played back below its original rate, which drags the pitch down with it, and the whole thing is pushed into a large reverberant space so the edges blur together. Done right it makes a familiar record feel like it is being remembered rather than played.
The pitch dropping is the part people get wrong. Modern editors default to time-stretching, which slows a track while holding the pitch where it was — useful for practising an instrument, wrong for this. This tool changes the playback rate instead, the way a tape machine would, so the vocal sits lower and heavier. That descent is the whole aesthetic.
Everything runs in your browser using Web Audio. Nothing is sent anywhere, there is no account, and there is no per-file cost, so you can push the sliders around until it sounds right instead of budgeting your attempts.

How it works
Three sliders and a download. No editor to learn.
MP3, WAV, FLAC, M4A — a video file works too, the audio track is pulled out of it. The file is read locally and never leaves your machine.
Speed around 85% is the classic setting. Reverb controls how much of the wet signal you hear; room size sets how long the tail rings on.
Preview in the page, adjust anything you do not like, run it again. When it sounds right, download the WAV.
What you get
Rate change, not time stretch. The bass sags, the vocal deepens, everything settles — that descent is what separates this from a track that is merely slow.
Anywhere from half speed to slightly sped up, in one-percent steps. Most of the genre sits between 80 and 90 percent; a few percent either way changes the whole mood.
Reverb amount and tail length are separate controls. A short tail thickens the track; a long one pushes it far away and makes the lyrics hard to follow, which is sometimes exactly the point.
The audio is decoded and processed by your own browser. Nothing is transmitted, nothing is stored on a server, and there is no account or credit system in the way.
Who uses it
The slowed version of a track is its own format on TikTok and Reels, and the pacing suits a slow edit far better than the original tempo.
A version of a song you already love, for the part of the night when the original is too bright.
The genre overlaps with lo-fi for a reason — slowing a track down and softening it removes most of what makes music distracting.
Something familiar, sitting far enough back in the mix that it does not fight with a voice over the top.
Producers run their own mixes through it to hear what the arrangement does at another tempo.
Push the speed slider past 100% instead and you get the other half of the format — same tool, opposite direction.
FAQ

Pick a song, move two sliders, hear it a few seconds later. Nothing is uploaded.