Deezer BPM

A browser extension for Firefox and Chrome that displays the BPM of songs on Deezer.

Features

• Floating badge — shows the BPM of the currently playing track in a fixed badge at the bottom-right of the page
• Playlist mode — shows the BPM next to each track in a playlist or album view, loaded lazily as you scroll
• BPM Selection & Filtering — select and filter tracks by BPM range using expressions like >120 or 124
• Persistent preference — playlist mode and other settings are remembered across sessions
• Localized — UI available in English and French

Screenshots

Installation

From a release (recommended)

Firefox

1. Download the latest .xpi file from the Releases page
2. Open Firefox and go to about:addons
3. Click the gear icon → Install Add-on From File…
4. Select the downloaded .xpi

Chrome

1. Download the latest .zip file from the Releases page
2. Unzip it
3. Open Chrome and go to chrome://extensions
4. Enable Developer mode (top-right toggle)
5. Click Load unpacked and select the unzipped folder

From source

1. Clone the repository

   git clone https://github.com/octogene/deezer-bpm.git

2. Open Firefox and go to about:debugging
3. Click This Firefox → Load Temporary Add-on…
4. Select deezer-bpm/manifest.json

Note: Temporary add-ons are removed when Firefox restarts. Use the signed .xpi for a permanent installation.

Usage

1. Navigate to deezer.com and play a track
2. A small circular BPM badge appears at the bottom-right of the page
3. To show BPM for every track in a playlist or album, click the ≡ button on the badge
   • The button turns bold green when playlist mode is active
   • BPM values appear next to the track duration column and load as you scroll
4. To filter or select tracks by BPM, click the filter icon on the badge
   • Enter an expression: >120 (greater than 120), <=90 (less or equal to 90), 120-130 (range), or 124 (exact match)
   • Matching tracks are highlighted and automatically checked in the playlist

How it works

BPM data is fetched from the public Deezer API (/track/{id}) — no API key required.

For playlist mode, the extension fetches the full track list from the API (/playlist/{id}/tracks or /album/{id}/tracks) and maps each visible row using Deezer's virtual list aria-rowindex attribute. Results are cached for the session so tracks are never fetched twice.

Development

The extension is a plain WebExtension (Manifest V3) with no build step.

deezer-bpm/
├── manifest.json
├── content/        # content script modules
├── styles.css      # badge and inline BPM tag styles
├── _locales/       # internationalization support
└── icons/          # extension icons

To work on it locally, load it as a temporary add-on (see From source above). After editing a file, click Reload in about:debugging.

Linting

We use ESLint to maintain code quality. To run the linter:

npm install
npm run lint:js

Documentation

For more details on how the extension works and a full FAQ, visit the official documentation at octogene.github.io/deezer-bpm.

Publishing a release

The CI workflow builds and signs the extension automatically when a version tag is pushed:

git tag v1.0.0
git push origin v1.0.0

This requires several repository secrets to be set (Settings → Secrets → Actions):

Secret	Description
AMO_API_KEY	AMO JWT issuer key (Firefox)
AMO_API_SECRET	AMO JWT secret (Firefox)
CHROME_EXTENSION_ID	The ID of your Chrome extension
CHROME_CLIENT_ID	Google OAuth2 Client ID
CHROME_CLIENT_SECRET	Google OAuth2 Client Secret
CHROME_REFRESH_TOKEN	Google OAuth2 Refresh Token

Generate Firefox secrets at addons.mozilla.org/developers/addon/api/key. For Chrome, follow the Google documentation to set up API access.

License

MIT