Observed arrival · 2026-09-30

What Key and BPM

whatkeyandbpm.com Visit website

Editorial interest 82/100 Selection signal · not a rating of the site

A browser-based tool that estimates an audio file’s musical key, tempo, and tuning, with a command-line version for processing folders.

Landing page captured for the 2026-09-30 issue.

For: DJs and people organizing sample libraries
Worth noticing: The page explains that tempo can reasonably resolve to half or double a listener’s expected pulse, rather than presenting every result as definitive.

Field notes

The page distinguishes key strength from a simple key label and warns that drum loops, effects, or heavily processed material may not have a stable key. Its tempo workflow presents an early estimate, a slower refinement, and a beat-grid listening check. The CLI instructions show tagging and optional renaming, and name Bun and ffmpeg as requirements.

Observed signals

Read the marks

Editorial observations of this landing page, not a rating.

○OpenPublic substance visible

✦PrettyNotable craft visible

●ProPolished or operationally mature

◎NicheUnusually specific use

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