Key & BPM Finder

Instantly detect the musical key and BPM (tempo) of any song or audio file. 100% free, no account required. Powered by AI audio analysis.

Free Tool - 0 Credits Required

Upload Audio File

Drag & drop your file here, or browse

Supports MP3, WAV, FLAC, OGG, M4A, AAC, AIFF, WMA. Max 50MB.

file.mp3

0 MB
Analysis typically takes 2-5 seconds
Analyzing audio...

Analyzing audio...

Detecting key signature, tempo, and musical characteristics
Analysis Complete
Musical Key
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--
BPM (Tempo)
--
--
Time Sig.
--
signature
Camelot Code
--
Camelot Wheel
Key Confidence --%
BPM Confidence --%
Tempo Visualization --

Camelot Wheel Position

--

Compatible Keys for Mixing

These keys are harmonically compatible for mixing, mashups, and smooth transitions. Move up or down by one Camelot number, or switch between A (minor) and B (major) for energy shifts.
Detected Key --
Relative Key --
Parallel Key --
Scale Notes --
Exact BPM --
Half / Double BPM --
Open Key Notation --
Track Duration --

Analysis History (This Session)

Track Key Camelot BPM Tempo

How It Works

  1. Upload any audio file (MP3, WAV, FLAC, OGG, M4A, AAC, AIFF, or WMA)
  2. Our AI analyzes the spectral and rhythmic content of the audio waveform
  3. Key detection uses chromagram analysis to identify the tonal center and mode
  4. BPM detection uses onset detection and autocorrelation for precise tempo measurement
  5. Results include Camelot codes, confidence scores, scale notes, and harmonic data

Tempo Reference Guide

Category BPM Range Typical Genre
Largo40-60Ambient, Drone
Adagio60-80Ballads, Downtempo
Andante80-100Hip Hop, R&B
Moderato100-120Pop, Reggae
Allegro120-140House, Techno, EDM
Vivace140-170Drum & Bass, Dubstep
Presto170-200+Speedcore, Gabber

Camelot Wheel Guide

The Camelot Wheel is a tool DJs and producers use for harmonic mixing. Each key is assigned a number (1-12) and letter (A for minor, B for major). For harmonically compatible transitions, mix tracks that are:

  • Same code (e.g., 8A to 8A) - Perfect harmonic match, zero tonal clash
  • Adjacent numbers (e.g., 8A to 7A or 9A) - Smooth key transition with minimal tension
  • Same number, switch letter (e.g., 8A to 8B) - Minor to major energy shift, great for build-ups
  • Plus one, switch letter (e.g., 8A to 9B) - Energy boost with dominant key resolution

Used by Rekordbox, Traktor, Serato, Mixed In Key, and VirtualDJ.

Supported Formats

MP3 WAV FLAC OGG M4A AAC AIFF WMA OPUS WebM

Maximum file size: 50MB. For best results, use high-quality audio files (WAV or FLAC). Higher quality input yields more accurate key and BPM detection.

Tips for Accurate Results

  • Use high-quality source files (WAV or FLAC) for best accuracy
  • Full-length tracks give more reliable results than short clips
  • Songs with clear harmonic structure are easier to analyze
  • If BPM seems wrong, check the half/double time suggestions
  • Songs that modulate (change key) may show the dominant key

How Key & BPM Detection Works

Advanced audio analysis algorithms examine the spectral and rhythmic characteristics of your music to determine its tonal center and tempo with high precision.

Step 1

Upload Your Files

Drag and drop any audio file onto the upload area, or click to browse your files. We accept all major audio formats including MP3, WAV, FLAC, OGG, M4A, AAC, AIFF, and WMA. Files up to 50MB are supported for thorough analysis of complete tracks.

Step 2

AI Analyzes the Audio

Our engine performs chromagram analysis to identify pitch classes and determine the tonal center and mode. Onset detection and autocorrelation algorithms precisely measure the tempo. The analysis runs server-side on GPU hardware for speed and accuracy, typically completing in 2-5 seconds.

Step 3

View Complete Results

See the detected musical key (major or minor), BPM with decimal precision, Camelot code for DJ mixing, Open Key notation, tempo category, scale notes, relative and parallel keys, and confidence percentages. Copy results or analyze more tracks to build a session history for setlist planning.

Voice Recorder Use Cases

A browser-based voice recorder is useful for countless scenarios, from quick voice memos to professional reference recordings.

DJing & Harmonic Mixing

The foundation of great DJ sets is harmonic mixing. Know the key and BPM of every track in your library so you can create seamless transitions between songs. Use Camelot codes to instantly identify compatible tracks. Mix in key to keep your audience engaged without dissonant clashes between songs. Essential for Rekordbox, Traktor, Serato, and VirtualDJ users who want to tag their libraries accurately.

Professional Audio Production

Convert compressed audio to lossless WAV or AIFF for editing in DAWs like Ableton, FL Studio, and Logic Pro. Ensure you work with the highest quality source material for mixing and mastering. Convert final masters to multiple delivery formats for distribution.

Mashups & Remixing

Creating mashups requires knowing the exact key and BPM of both source tracks. Use our tool to identify compatible songs, then pitch-shift or time-stretch as needed. The Camelot system makes it easy to find songs that will blend naturally, even across different genres and decades. Analyze entire playlists to find the best mashup candidates.

Karaoke & Vocal Performance

Find the key of any song to determine if it falls within your vocal range. Singers and vocal coaches use key detection to identify whether a track needs to be transposed up or down for a comfortable performance. Essential for karaoke hosts who need to quickly adjust songs for different singers at live events.

Music Education & Theory

Music students and teachers use key and BPM detection for ear training, music theory exercises, and analyzing compositions. Verify your ability to identify keys by ear, study the tempo patterns of different musical eras and genres, and build a deeper understanding of harmonic structure across the repertoire you

Video Editing & Content Creation

Content creators and video editors use BPM data to sync cuts, transitions, and effects precisely to the beat of background music. Knowing the tempo ensures your visual edits land on musical beats, creating more professional and engaging video content for YouTube, TikTok, Instagram Reels, and other platforms.

Why Use Our Free Voice Recorder?

Precise Key Detection

Our key detection algorithm uses chromagram analysis, which maps audio frequencies to the twelve pitch classes of the Western chromatic scale. By analyzing the distribution and prominence of these pitch classes across the entire track, we determine the most likely tonal center and whether the piece is in a major or minor key. The algorithm handles complex harmonies, key changes, and modal ambiguity, providing confidence scores so you know how certain the result is.

Accurate BPM Detection

Tempo detection combines onset detection (identifying the start of musical events like drum hits and note attacks) with autocorrelation and spectral flux analysis to find the dominant periodicity in the audio. Our algorithm accurately handles complex rhythms, syncopation, tempo changes, and genres with ambiguous beat patterns. Results include decimal-precision BPM values and half/double time alternatives for genres like drum and bass or hip-hop where the perceived tempo can differ.

Camelot & Open Key Notation

Every detected key is automatically converted to both Camelot notation (used by Mixed In Key, Rekordbox, Traktor, and Serato) and Open Key notation. This makes it effortless to identify harmonically compatible tracks for mixing. The Camelot system assigns each key a number from 1-12 and a letter (A for minor, B for major), so compatible keys are always adjacent on the wheel. We also show relative keys, parallel keys, and compatible key lists.

Completely Free & Unlimited

Unlike other key and BPM detection tools that limit free usage or require subscriptions, our Key & BPM Finder is completely free with no limits. Analyze as many tracks as you want, as often as you want, with no account required. No credits consumed, no watermarks, no hidden restrictions. All processing happens on our servers, so it works on any device with a browser, including phones and tablets.

Frequently Asked Questions

Our tool uses spectral analysis (via librosa) to detect the musical key and tempo of audio. It analyzes the frequency content to determine the key using chromagram analysis, and uses onset detection and autocorrelation to find the tempo (BPM).

BPM detection is typically 95%+ accurate for music with a clear beat. Key detection is 80-90% accurate and may occasionally suggest a relative key (e.g., A minor instead of C major). Complex or atonal music may produce less reliable results.

Yes, key and BPM detection is completely free with no account required and no usage limits. It uses zero credits for all users.

Camelot notation is a DJ-friendly system that maps musical keys to numbers and letters (e.g., 8A = A minor, 8B = C major). Compatible keys are adjacent on the Camelot wheel, making harmonic mixing easy. Our tool shows both standard key names and Camelot notation.

We support MP3, WAV, OGG, FLAC, M4A, and WEBM files up to 50MB. The tool analyzes the full audio spectrum regardless of format, though higher-quality files (WAV, FLAC) may produce slightly more accurate results.

Absolutely. The key and BPM information is essential for harmonic mixing. Use the detected key and Camelot notation to find compatible tracks, and match BPMs for smooth transitions. This tool replaces manual key detection with instant AI analysis.

The web interface processes one track at a time. For batch analysis of entire music libraries, use our API to detect key and BPM for multiple files programmatically and build a tagged database of your collection.

The tool works best on individual tracks with a consistent key and tempo. DJ mixes or live recordings with tempo changes and key modulations may produce averaged or less reliable results. For mixes, consider analyzing individual segments separately.

The tool reports the primary key of the track. Songs with key modulations (key changes) will show the dominant key. For detailed key-change analysis throughout a song, you can use the API to analyze shorter segments of the track individually.

Yes, the tool distinguishes between major and minor keys (e.g., C major vs. A minor). It also shows the relative major/minor key since these share the same notes but have different tonal centers. The Camelot notation reflects this with A (minor) and B (major) designations.

The tool primarily detects tempo (BPM). While it is optimized for common time (4/4), it can detect BPM in other time signatures like 3/4 or 6/8, though the reported BPM may need interpretation based on the actual time signature of the piece.

Detect the key and BPM of both tracks you want to combine. For a smooth mashup, choose tracks in the same or compatible keys (adjacent on the Camelot wheel) and similar BPMs. You can pitch-shift or time-stretch to align tracks that are close but not exact matches.
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