Key & BPM Changer

Method

How It Works

1. Drop a track; its current key and BPM are detected by the same engine as our Song Key & BPM Finder
2. Type the exact BPM you want, or use the quick 85/90/110/125 percent presets
3. Pick a target key; the semitone shift is computed from the Camelot wheel automatically
4. Processing runs locally (Signalsmith Stretch, a high-quality open time-stretch engine), then the output is re-analyzed to confirm it landed on your targets

Exact BPM, Not Percentages

The common complaint about online tempo changers is that they only move speed by percentages, leaving you to work out what 6 percent faster means in beats per minute. Because this tool detects the source tempo first, you work in BPM directly: a 122 BPM track that needs to sit in a 126 set is one number away. The precise stretch ratio, down to the detected decimal, is handled for you, and the re-analysis step shows the output BPM so you are not taking it on faith.

Slowed, Sped Up, and Vinyl Mode

By default, tempo changes preserve pitch (time-stretching) and key changes preserve tempo (pitch-shifting), independently. Vinyl mode links them the way a turntable does: slow the track down and the pitch drops with it. That is the sound of classic slowed edits (around 85 percent speed) and, in the other direction, sped-up and nightcore-style versions (115 to 125 percent). The quick percentage presets under the BPM field cover both.

Transposing for Harmonic Mixing

Re-keying a track opens transitions that the original key forbids: shift an acapella two semitones to sit on your instrumental, or nudge a melodic track one semitone so it becomes Camelot-compatible with the next record. The target-key dropdown shows every same-mode key with its semitone distance, and the key compatibility checker and Camelot wheel tell you which targets are worth aiming for. Keep shifts small: one or two semitones pass unnoticed on full mixes, while larger moves start to color the timbre.

Private by Architecture

Like our analyzer, this tool does all of its work in your browser: decode, stretch, transpose, encode. Unreleased edits, premieres, and your own productions never touch a server. That is also why it is free without limits; there is no processing bill to recover.

Frequently Asked Questions