osu! beatmap generator for osu!mania

From MP3 to .osz in three steps

1. Drop a song into the editor — MP3, OGG, WAV, FLAC or M4A.
2. Generate. The song is analysed on your device and you get Easy, Normal and Hard charts. Audition them right in the browser before you export.
3. Click "Export osu!mania (.osz)". Open the downloaded file and osu! imports it as a beatmap set with the audio, a timing point at the detected BPM and all three difficulties (CS 7, OD 6/7/8).

What the generator does

Charting a song by hand takes hours: find the BPM, set the offset, then place every note. The generator does those steps automatically:

• Tempo detection — estimates BPM and builds a beat grid so notes snap to the music.
• Onset detection in three bands — low (kick drum), mid (melody) and high (hi-hats) are tracked separately, because they play different roles in a chart.
• Difficulty by layering, not by density — Easy charts the melody; Normal adds the rhythm section on strong beats; Hard adds chords, brackets and long notes on top. This is how O2Jam-style charts were written, and it is why the generated maps read as music rather than noise.
• Column assignment — notes are spread across 7 columns so hands alternate naturally and jacks (the same key hit repeatedly) stay rare on lower difficulties.

How it compares to mapping by hand

A generated map will not replace a carefully hand-crafted ranked map — a human mapper can emphasise a vocal line or a key change in a way an algorithm misses, and generated maps are not eligible for ranking. What the generator gives you is a solid, playable chart in seconds for songs nobody has mapped yet, or a starting point to refine in the osu! editor. It is tuned against a reference set of real O2Jam charts, comparing long-note ratios, column usage and chord density per difficulty.

Play it here too

You do not need osu! to play the result: every chart also plays right on BeatCombo with S D F Space J K L, PERFECT / GREAT / GOOD / MISS judgements, latency calibration and a practice mode. Publish it and it gets its own page and leaderboard.

Questions

Is the osu! beatmap generator free?

Yes, completely. It runs in your browser, so there is no queue, no account needed to generate or export, and your audio is not uploaded unless you choose to publish.

Is it an AI beatmap generator?

It uses signal processing (spectral-flux onset detection and tempo tracking) plus rules learned from real charts, rather than a large neural network. That keeps it fast enough to run entirely on your device — a few seconds per song instead of a GPU notebook.

Does it make osu!standard or 4K maps?

Not yet — output is osu!mania 7K. You can change the key count in the osu! editor, but the notes are laid out for seven columns.

Can I upload generated maps to the osu! website?

Only for songs you have the rights to, and check osu!'s rules on auto-generated maps first. For personal play, just import the .osz.