# BPM Detector - Find the Tempo of a Song Online, with Beat Markers & Tap Tempo

> Free online BPM detector: find a song's tempo to 0.1 BPM with a confidence score and half/double-time candidates, see every beat on the waveform, or tap along.

- URL: https://qilingtools.com/en/audio/bpm
- Category: Audio Tools (https://qilingtools.com/en/audio)
- Tags: [Audio](https://qilingtools.com/en/tags/audio), [Music](https://qilingtools.com/en/tags/music)
- Last updated: 2026-10-26
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

DJs, video editors cutting to the beat, choreographers and musicians practising with a metronome all need a song's BPM. Drop in a track and the tool decodes it in your browser, builds an onset-strength curve, finds the strongest beat period with autocorrelation, then tracks each beat with dynamic programming and fits the exact tempo — reported to 0.1 BPM with a confidence score. Because music is often ambiguous between half-time and double-time (70 vs 140), several candidates are listed; click one and the red beat markers on the waveform follow. Hit Play with click track to hear the beats over the music and confirm by ear. You can analyze just a section, such as a chorus with clear drums, for a more reliable result, and there is a manual tap-tempo counter below (click or press T). Formats the browser cannot decode, such as WMA, are converted with FFmpeg automatically.

## How to use

1. Upload an audio file (MP3, WAV, M4A, FLAC, OGG…) or a video — analysis starts automatically
2. Review the BPM, confidence and candidates; pick a section with a clear beat and re-run if needed
3. Play with the click track to verify, or tap along to double-check

## Features

- Automatic BPM detection to 0.1 BPM
- Confidence score with a warning for weak rhythm
- Half-time / double-time candidates, one click to switch
- Beat markers drawn on the waveform
- Click-track playback to verify by ear
- Analyze a selected segment only
- Manual tap tempo (button or T key)
- Works with video files; WMA and similar are converted automatically

## FAQ

### The result is half or double the real tempo — why?

That is the classic ambiguity of beat detection: a 140 BPM track can also be felt at 70. The detector prefers the most common tempo range around 60–180 BPM but always lists the half and double values as candidates. Click a candidate and play the click track to choose the one that matches how the song feels.

### Why is the confidence low for some songs?

Classical music, rubato ballads, free-time intros and sections without percussion have a weak or changing pulse, which is hard to detect automatically. Select a chorus with clear drums and detect again, or use the tap tempo below. For songs whose tempo drifts, the result is the average over the selected segment.

### Are my files uploaded to a server?

No. Everything runs locally in your browser via WebAssembly. Files never leave your computer and are discarded when you close the page.

### Do I need to sign up or pay?

No. The site is completely free, requires no account, has no usage limits and adds no watermarks.

## Related tools

- [Convert Audio](https://qilingtools.com/en/audio/convert): Free online audio converter: convert between MP3, WAV, M4A, AAC, FLAC, OGG and OPUS with selectable bitrate. Powered by FFmpeg, processed locally, no upload.
- [Trim Audio](https://qilingtools.com/en/audio/trim): Free online audio trimmer: set start and end times to cut a clip from MP3, WAV, M4A and more. Make ringtones. Processed locally, no upload.
- [Merge Audio](https://qilingtools.com/en/audio/merge): Free online audio merger: join MP3, WAV and other audio files in order into one file, mixed formats supported. Processed locally, no upload.
- [Volume / Speed](https://qilingtools.com/en/audio/volume): Free online audio volume booster: amplify or reduce volume and change playback speed (0.5x to 3x without pitch change). Processed locally, no upload.
- [Audio Fade In/Out](https://qilingtools.com/en/audio/fade): Free online audio fade tool: add a fade-in at the start and a fade-out at the end of MP3, WAV and more, with any length. Batch supported, runs locally.
- [Normalize Audio](https://qilingtools.com/en/audio/normalize): Free online loudness normalizer: bring a batch of files to the same perceived loudness with EBU R128 / LUFS, or even out uneven speech with compression.
- [Split Audio](https://qilingtools.com/en/audio/split): Free online audio splitter: cut long recordings, album rips and audiobooks into parts by count, fixed length or specific time points, downloaded as a zip.
- [Mix Audio](https://qilingtools.com/en/audio/mix): Free online audio mixer: play voice, a backing track and background music together, with adjustable levels and a built-in limiter. Processed locally.