BPM Finder & Key Finder for Songs
Detect a song's tempo, musical key, mood, energy and more in seconds. Drop any audio file for private, on-device analysis right in your browser.
How Song Tempo and Key Detection Works
Three simple steps to find the BPM and key of any song
1. Upload Your Audio File
Drag and drop or click to upload any audio file. It supports MP3, WAV, FLAC, AAC, OGG, M4A and more.
2. Instant Browser Analysis
Our audio engine analyzes your file entirely inside your browser using advanced signal processing. No data is uploaded to any server.
3. View Detailed Results
Get accurate BPM, musical key, mood classification, energy level, loudness measurement, and danceability score in seconds.
Why Musicians Use This Tempo & Key Analyzer
Powerful, private, and completely free
100% Private
Your audio never leaves your device. All tempo and key detection is performed locally in your browser — no file uploads, no server processing, no data collection.
Lightning Fast
Powered by a WebAssembly audio engine, the analyzer returns tempo and key data in seconds — even for longer tracks. No waiting for server responses.
Multi-Parameter Analysis
Go beyond tempo. It also detects musical key and scale, mood classification, energy level, spectral brightness, dynamic range, and danceability.
DJ & Producer Friendly
Whether you're beatmatching, choosing the right key for a mashup, or organizing your music library, our tool gives you the data you need to mix and produce like a pro.
Works Everywhere
No installation needed. It works on any modern browser — desktop, tablet, or mobile. macOS, Windows, Linux, iOS, and Android are all supported.
Free, No Limits
Analyze as many tracks as you want. No sign-up, no daily caps, no premium tiers. The tool is free to use.
Tempo & Key Detection FAQ
Common questions about BPM detection and key finding
How accurate is the tempo detection?
Our tempo detection algorithm is highly accurate for most genres of music. It uses Percival's BPM estimation method, which performs well across electronic, pop, rock, hip-hop, and classical music. For tracks with complex time signatures, results may vary by ±1–2 BPM.
How does the key detection work?
The tool detects the musical key and scale (major or minor) of a song. It uses spectral analysis and chromagram-based algorithms to determine the tonal center — essential for harmonic mixing, mashups, and music production.
Is my audio uploaded to a server?
No. Your audio file is processed entirely in your browser using WebAssembly technology. Nothing is uploaded, transmitted, or stored on any server. Your audio stays 100% on your device.
What audio formats are supported?
The analyzer supports any audio format your browser can decode: MP3, WAV, FLAC, AAC, OGG, M4A, MP4, WebM, and more. File size limit is 50MB.
Can I use this tool for DJing?
Absolutely. DJs use tempo and key data to beatmatch tracks and keep harmonic mixes compatible between songs. This tool provides both, making it a strong companion for live sets and playlist preparation.
How is the mood detected?
Mood detection uses a combination of danceability scoring, spectral energy analysis, and dynamic range measurement. The algorithm classifies tracks into moods like High Energy, Groovy, Neutral, or Atmospheric — giving you a quick feel for the track's vibe.
Why do I get different BPM results compared to other tools?
Different BPM detectors may measure half-time or double-time tempos differently. For example, a 140 BPM track could be reported as 70 BPM by some tools. Our finder reports the most likely perceived tempo. The key detection algorithm is generally consistent across tools.
Do I need to create an account?
No. You can use the analyzer for free without any registration, login, or email. Just open the page and start analyzing.