/ Free online tool — BPM detector & tester

Drop a file.
Find the tempo.

The same tempo detection that runs inside Sample Vault, in your browser. No upload. No sign-up.

Click or drop audio.

WAV, MP3, FLAC, OGG, M4A, or AAC.

/ Method

How the BPM detector
works.

Method: onset detection + autocorrelation with grid reconciliation · Built by Sample Vault

The same tempo detection the desktop app runs against your library, in your browser.

/ 01 — Onset tracking

We track where transients land — every kick, snare, and pluck — frame by frame. That gives a list of onsets the tempo detector can lock onto.

/ 02 — Tempo locking

Autocorrelation on the onset envelope finds the period that best repeats. For loops, the file's own length gets cross-checked against common bar counts — that's how a 4-bar loop confidently reports the right BPM rather than a half or double.

/ 03 — Honest failure modes

Atmospheric pads, sustained notes, sparse FX and anything without enough transients return no tempo instead of a confident guess. Low-confidence results are surfaced as estimates, not facts.

/ 04 — Fully local

The file never leaves your machine. Loads once, runs offline thereafter. Useful for unreleased material, label stems, and anything you can't put through a third-party service.

/ Across your library

From one file
to fifty thousand.

Detecting tempo on one file is a party trick. Detecting it on 40,000 files, organising the result, and letting you pull every 138 BPM loop in F minor with a sub-heavy bass in under a second — that's the desktop app. Same engine, run across every folder you point it at.

Download for FreeRead the use case

/ Embed on your site

Put it on
your page.

Free to embed on any blog, forum, or lesson page. Paste the snippet where you want the bpm detector to appear. Analysis runs in the reader's browser — nothing is uploaded.

<iframe src="https://samplevault.ai/embed/bpm-detector" title="Free BPM detector by Sample Vault" width="100%" height="560" loading="lazy" style="border:1px solid #262626;width:100%;max-width:680px"></iframe>
<p style="font:12px/1.5 system-ui,sans-serif;margin:8px 0 0">Free <a href="https://samplevault.ai/tools/bpm-detector" target="_blank" rel="noopener">BPM detector</a> by <a href="https://samplevault.ai" target="_blank" rel="noopener">Sample Vault</a></p>

/ More free tools

All free tools →

Key & scale detector.

Drop a file, get the key. Same engine as the BPM detector, with a chromagram of tonal content.

Mono-compatibility checker.

Drop a stereo file, see which bands collapse when summed to mono. Per-band phase analysis, runs locally.

/ 09 — FAQ

BPM detector — frequently asked questions

Tempo detection questions, answered straight.