Offline Key and BPM Analyzer: how BeatScope works

The BeatScope team · updated July 14, 2026 · ~4 min read

Looking for a key and tempo analyzer that works without the internet and doesn't ask for a subscription? Here's what to look for — and how BeatScope covers each point: offline, free, with cues and tags written straight into rekordbox and Serato.

The key/BPM detector category is well established, and there are good tools in it. We won't line anyone up for a head-to-head — we'll just lay out what matters and show, honestly, how it works on our side.

1. Offline and on-device

The main practical criterion at the booth is whether analysis works without a connection. In BeatScope everything is computed locally: tracks aren't uploaded to a server. That's faster, more private (your music never leaves the device) and it works in a club with no internet.

2. Method accuracy

Accuracy comes from the algorithm, not magic. BeatScope uses an academic approach: a chromagram correlated with Krumhansl–Schmuckler profiles for key, and autocorrelation of an onset envelope for tempo — the same methods that underpin studio key detectors (libKeyFinder). Full breakdown in "How BeatScope Detects Key and Tempo".

3. Cues and tags — in rekordbox and Serato formats

Analysis is useful when the result lands in your deck. BeatScope writes hot cues into the file in rekordbox and Serato formats, and key, BPM and energy tags are compatible with rekordbox, Serato and Traktor. Open the track in any system and the data is already there.

4. Camelot for harmonic mixing

Key is returned both in notes and in Camelot code — transitions are picked on the wheel. See how in the Camelot wheel guide.

5. Price and platforms

BeatScope is free, ad-free and with no mandatory subscription, on macOS 12+ and iPhone (iOS 15+). The mobile version isn't a cut-down copy but a pocket kit with live analysis and utilities (see the mobile write-up).