Free Online DJ Tools
Change BPM, convert audio, and keep every file local in your browser.
Convert audio files between formats directly in your browser. No upload required — everything runs locally.
Auto-detect BPM, adjust tempo, preview in real time, and export — all processing happens locally in your browser.
Check whether a track is really 320 kbps or truly lossless — the spectrogram is rendered locally in your browser, files never leave your device.
Transpose songs up or down in semitones without changing tempo — all processing happens locally in your browser.
Choose the right tool for the job
SirenMix focuses on high-intent DJ tasks: changing tempo safely and converting audio formats without upload friction. The tools are lightweight enough for quick prep but built around real DJ constraints like privacy, compatibility, and speed.
Use BPM Changer when you need to test tempo moves, preserve pitch, and export a new version before a set.
Use Audio Converter when a track needs a different delivery format for playback hardware, storage, or sharing.
Read the linked guides when you need the theory behind the workflow, not just the output file.