Finding a BPM with AI and audio

Ask AI for the BPM

Choose Ask AI for BPM in the menu or press A, then type a song or artist (up to 50 characters). When the candidates show up, press Apply to use that BPM.

In progressive mode, only the current BPM changes and the range is kept. If the candidate is outside the range, the range is widened to include it.

AI is not always right. Listen to check, and adjust with − + if needed.

Ask AI to edit your settings

Choose Ask AI to Edit Settings in the menu and describe what you want, such as “raise the BPM by 10 every bar” (up to 280 characters). After it is applied, press Undo in the toast to go back.

Measure an audio file

Choose Detect BPM from Audio in the menu to open the BPM analysis screen, then press CHOOSE FILE to pick an audio file. You can also drop an audio file on the metronome screen or on the analysis screen. Besides mp3 and wav, it reads m4a, flac, ogg and more.

When the analysis finishes, the detected BPM appears and the song starts playing with clicks on the detected beats. The waveform at the top marks each beat with a line, and the line in the accent color shows the playback position.

• Play / pause: the play cell or the Space key. Playback resumes where you paused
• Click the waveform: play from that point
• HALF / DETECTED / DOUBLE: pick again when the tempo sounds half or double. The BPM, the beat lines and the clicks switch without stopping playback
• Play with beat clicks: whether to play clicks on the beats
• Auto-scroll the waveform: keeps the playback position in view. Scrolling the waveform during playback turns it off; turning it back on jumps to the playback position
• AUDIO VOLUME: the volume of the song. It is kept for next time
• APPLY THIS BPM: sets the metronome to the selected BPM
• Check with AI by song name: has AI look up the song's BPM from the file name

• Play / pause (while the BPM analysis screen is open)Space

Closing the screen stops playback, but the analyzed audio stays. Choose Detect BPM from Audio in the menu again to reopen it as you left it. To measure another song, press OTHER FILE.

Beat positions are estimated from the sound and may be off for some songs. Even when a live performance drifts in tempo, the clicks follow the estimated beats.

Measure live

Choose Detect BPM Live in the menu and it starts listening through your microphone right away. It keeps estimating the BPM while it listens, so you can measure songs you have no file for, music playing from a speaker, or a live performance. The first time, your browser asks for microphone permission.

After about 4 seconds of audio, the BPM appears. It keeps updating every second, and the stability shows how well the recent estimates agree. Once the estimates agree and the tempo is settled, beat lines appear on the waveform. Applying after the stability rises gives the most reliable result.

The waveform at the top scrolls in from the right as the microphone hears it. The accent-color line at the right edge is now, and lines mark the detected beats. When the lines sit on the peaks of the sound, the estimate is right.

• STOP / LISTEN AGAIN: stops or restarts listening. The last BPM and waveform stay, so you can still apply it
• Play clicks on the beats: plays the same click as the audio file analysis on the detected beats, so you can hear whether they line up (off at first; once turned on, it stays on next time)
• HALF / DETECTED / DOUBLE: pick again when the tempo sounds half or double. The beat lines and clicks switch too
• APPLY THIS BPM: sets the metronome to the selected BPM

• Stop / listen again (while the Detect BPM Live screen is open)Space

The metronome stops while listening, so the microphone does not pick up its sound. Closing the screen stops listening and the clicks.

Where the beat is unclear, such as when the drums drop out, it keeps the tempo it settled on and keeps clicking at that tempo. When it is clear the tempo has changed, it switches to the new one.

Quiet music works too, but loud surrounding noise makes the estimate unsteady. Moving the microphone closer to the source helps. Clicks played through speakers are kept from skewing the estimate, but headphones are the most reliable.