An Audio Pitch Changer that uses playback-rate resampling changes pitch and duration together, so the semitone value, source duration, output budget, and intended use all matter.
The Audio Pitch Changer provides a direct way to raise or lower the perceived pitch of one local audio file, but it is not a general-purpose time-stretching editor. Understanding what will change, what the browser must decode, and what the final WAV contains helps you choose a sensible shift and recognize when the method is unsuitable.
The pitch-and-duration trade-off
The tool accepts a whole-number pitch shift from −12 through +12 semitones. A negative value lowers the pitch, a positive value raises it, and zero retains the original pitch. Twelve semitones equal one octave, so −12 moves the material down one octave and +12 moves it up one octave.
The playback rate is calculated as 2^(n/12), where n is the selected number of semitones. This follows twelve-tone equal temperament. McGill University’s MIDI and frequency reference explains that an octave contains twelve equal semitones and that one semitone corresponds to 100 cents. MDN’s playbackRate documentation also describes how a rate above one speeds up audio, a rate below one slows it down, and a non-unit rate causes resampling.
| Selected shift | Playback rate | Effect on the audio |
|---|---|---|
| −12 semitones | 0.5× | Pitch falls by one octave; the result becomes longer and slower, with roughly twice the original duration. |
| 0 semitones | 1× | The original pitch is retained. |
| +12 semitones | 2× | Pitch rises by one octave; the result becomes shorter and faster, with roughly half the original duration. |
This distinction is central when choosing a pitch change. The tool does not preserve tempo, speech cadence, beat positions, or exact original duration. If a production requires the same duration after changing pitch, use a dedicated phase-vocoder or another time-stretching workflow instead.
Source-file and browser requirements
Begin with one browser-decodable audio file. The encoded file must be no larger than 50 MiB. Common input types include MP3, WAV, M4A, AAC, Ogg, WebM, and FLAC, but a recognized extension does not guarantee that every unusual codec profile will decode. Actual compatibility depends on the current browser, so test the source before relying on a particular format.
The file size is only the first check. After decoding, the audio must be no longer than five minutes, use no more than eight channels, and have a sample rate from 8,000 through 192,000 Hz. The decoded input is also limited to 30 million channel samples. Empty files, unsupported types, invalid decoded dimensions, and failed decodes are rejected.
These requirements matter because a file can be small enough on disk yet still be too long or too large after decoding. They also explain why a source that opens in one browser may not work in another.
Create the pitch-shifted WAV
- Choose the source file. Open the Audio Pitch Changer and select one browser-decodable file. Confirm that its encoded size is no more than 50 MiB and that it satisfies the decoded duration, channel, sample-rate, and sample-budget limits.
- Select the semitone value. Choose a whole-number shift from −12 through +12. Account for the linked speed and duration change, especially when shifting downward because the output will need more frames.
- Create the complete local render. The browser decodes the source, calculates the playback rate, and renders through an Offline Audio Context at the decoded sample rate. The required output dimensions are checked before the complete file is encoded.
- Review the stated duration change. Check the reported duration before downloading. A successful render contains the complete output; if the output exceeds its channel-sample budget or the browser cannot allocate it, the tool reports an error and creates no download.
- Download and inspect the PCM16 WAV. Save the newly encoded WAV and open it in a trusted local player. The page intentionally does not provide a blob-backed audio preview, so listening to the downloaded file is the practical review step.
Changing the input or semitone value invalidates the previous result. Download the current render rather than assuming an earlier file still represents the new selection.
Input and output budget checks
The decoded input and rendered output have separate 30-million-channel-sample limits. This distinction is especially important for downward shifts. Slowing the playback makes the result longer, so a file that fits the input budget can still generate an output that exceeds the output budget.
The complete output length is calculated before allocation. If the requested render would exceed the declared budget, the tool reports that the shift is over budget and does not truncate the result. There is also no fallback that substitutes an incomplete file. Browser allocation failure produces an error rather than a partial WAV, and the render is accepted only when its channel count, sample rate, and full frame count match the expected output.
Output format, quality, and metadata
The download is a new, uncompressed RIFF/WAVE file containing interleaved, little-endian PCM16 audio. It is not a renamed copy of the input. The original codec, compression quality, bitrate, tags, artwork, chapters, cue points, loop metadata, and other container metadata are not preserved. Floating-point samples are clipped to the legal −1 through +1 interval before conversion, and PCM16 quantization can differ from the decoded floating-point source.
Browser resampling quality is implementation-defined. Strong upward shifts may make aliasing or codec artifacts more obvious, especially if they were already present in the source. Listen through the entire result, especially its quiet passages, transients, and sustained notes. Because of these factors, the output is better suited to quick creative experiments, practice tracks, sound effects, and rough editing than to a transparent mastering process.
- Confirm that the downloaded file opens and plays to the end.
- Compare its duration with the stated change rather than the original duration.
- Listen for clipping, harshness, smearing, or familiar source artifacts.
- Keep the original file as the master instead of treating the PCM16 export as an unchanged copy.
- Use a time-stretching method instead if duration or tempo must remain fixed.
Choose the right workflow for the result
A modest shift can be useful for trying a different register, creating a practice version, or resizing a sound effect for an edit. Larger shifts have stronger effects on speed and duration, so the original intent should guide the amount. The exact audible result still depends on the source material and browser resampling, which is why listening to a completed download is essential.
Do not choose this workflow solely because the goal says “change pitch without changing speed.” That requirement calls for a time-stretching or phase-vocoder process. This tool is appropriate when linked pitch, speed, and duration changes are acceptable and you want a complete local PCM16 WAV.
Privacy and playback after download
File reading, browser decoding, offline resampling, and WAV encoding all run locally in the current tab. Processing and sample data remain in that tab, and no source audio or rendered audio is uploaded to Lizely.
Local processing does not replace an output review. The tool creates the downloadable file but no in-page preview. Play that file in a trusted local application, confirm the duration, and assess the pitch and resampling quality before using the result in a larger project.
If you're weighing options, When Should I Use an Audio Speed Changer? covers this in detail.
If you're weighing options, How Do I Make Sure I Use Volume Changer Correctly? covers this in detail.