Loop Trainer

Frequently asked questions

Short answers to common questions. For step-by-step instructions, see the guide.

Is Loop Trainer free?
Yes. It is free to use, with no sign-up or account.
Is my audio uploaded?
No. The file is read and played only in your browser. Nothing about your audio is sent anywhere. See the privacy policy.
Which files can I open?
MP3, AAC (m4a), and WAV work in every browser. FLAC, Ogg, and others work where the browser supports them. Video files with an audio track (such as MP4) often work too.
Can I use songs from Apple Music, Spotify, or YouTube?
No. Music from streaming services is protected and cannot be opened in other apps. Use audio files you have, such as songs you bought as files, recordings of your band, or practice tracks.
Does slowing down change the pitch?
No. The speed (50%–150%) and the key (±6 semitones) are changed separately, so you can use either one, or both together.
Why can't I go slower than 50%?
Below that, the sound is stretched so much that notes blur and it stops being useful for practice.
The loop points do not land on the beat.
Check the tempo next to the time: if it shows half or double the tempo you feel, use ½ or ×2 under “Beats and bars”. If the song has no steady beat, the app shows “No beat found”; place the points freely then. See beats and bars.
The bar starts are on the wrong beat.
The bar starts are a guess, made from where the chords change and from the bass and kick drum. Move them with ◀ ▶ next to “Bar starts”, and check the beats per bar (3 for a waltz).
Are my loops saved?
Yes, in your browser, for each song (recognised by the file name and size). Open the same file again and the loops, speed, and key come back. The audio itself is not saved. If you clear the site data, or use a private window, they are lost.
Can I use it offline?
Yes, after you have opened one file while online (the audio library is saved then). You can also install it: “Install” in Chrome or Edge, or Share → Add to Home Screen on iPhone and iPad.
There is no sound on my iPhone.
Tap Play once (phones only allow sound after a tap), and check the volume. On iOS 17 or later the app plays even when the silent switch is on; on older versions, turn the silent switch off.
A long file is slow or does not open.
Decoded audio needs about 20 MB of memory per minute. On phones, files of more than about 10 minutes can be too large. Cut the part you want to practise into a shorter file.