Why does the downloaded file have a different duration?

Audio Pitch Changer uses playback-rate resampling. Raising pitch speeds up and shortens the audio, while lowering pitch slows it down and lengthens it. It is not a fixed-duration time-stretching tool.

Why can lowering pitch fail after the source passes validation?

The decoded input and shifted output have separate 30-million-channel-sample limits. A negative shift increases the required output length, so a valid source can exceed the output budget; the tool then reports an error and creates no download.

What should I try if my audio file is rejected?

Confirm the encoded file is no larger than 50 MiB, then check that it is not empty and can decode in your browser. Also verify the decoded duration is at most five minutes, channel count is at most eight, sample rate is from 8,000 to 192,000 Hz, and decoded channel samples do not exceed 30 million.

Is my source audio uploaded?

No. File reading, browser decoding, offline resampling, and PCM16 WAV encoding run locally in the current tab. The source and rendered audio are not uploaded to Lizely.

How to Troubleshoot an Audio Pitch Changer Problem

Troubleshoot Audio Pitch Changer by checking the browser-decodable source, the -12 to +12 semitone setting, and the separate 30-million-channel-sample output budget before rendering again. When you troubleshoot a problem when you use Audio Pitch Changer, the browser decodes one local file, applies a whole-number pitch shift, and renders a complete PCM16 WAV using playback-rate resampling. That method raises or lowers perceived pitch and changes speed and duration together, so a shorter or longer result is not automatically a failure. The encoded source must be no larger than 50 MiB. Decoded audio is limited to five minutes, eight channels, a sample rate from 8,000 through 192,000 Hz, and 30 million channel samples. The shifted output has its own 30-million-channel-sample limit. If the complete result cannot be rendered within that budget, the tool reports an error and creates no download rather than truncating the audio. File reading, decoding, resampling, and WAV encoding happen locally in the current browser tab, so an unfamiliar codec profile that the browser cannot decode can be the real problem even when the filename has a familiar extension.

how do i troubleshoot a problem when i use audio pitch changer — How to Troubleshoot an Audio Pitch Changer Problem

Separate a failed render from an expected result

Start by identifying where the workflow stopped. A rejected source needs file or browser troubleshooting. A render error needs a limit check. A completed render that sounds or lasts differently may simply reflect the tool’s playback-rate method.

Source rejected: No pitch shift was produced. Check the format, encoded size, decoded dimensions, and sample budget.
Render failed: No download is created. This usually points to the output budget or an allocation failure rather than an unwanted pitch setting.
Download has a different duration: Duration changes are expected when pitch changes because playback rate changes too.
Download sounds rough: Browser resampling, an upward shift, source-codec artifacts, or clipping may be responsible.

Changing the input file or semitone value invalidates the previous result. Create a fresh render after either change instead of assuming that a file downloaded earlier reflects the new setting.

Check the source file before rendering

Audio Pitch Changer accepts common browser-decodable MP3, WAV, M4A, AAC, Ogg, WebM, and FLAC inputs. Actual codec support still depends on the current browser, so a recognized extension does not guarantee that every unusual codec profile will decode.

Select one nonempty file whose encoded size is no more than 50 MiB.
Confirm that the browser can decode it. A file that will not open in a trusted local player is unlikely to work reliably in the browser tool either.
Check that the decoded duration is at most five minutes, the channel count is at most eight, and the sample rate is from 8,000 through 192,000 Hz.
Make sure decoding does not exceed 30 million channel samples.

If the source is rejected, first try exporting it again in a common browser-decodable format. Shorten it if it exceeds the decoded duration or sample limits. Do not repeatedly convert an otherwise valid file; once it passes source validation, the next likely constraint is the shifted output budget.

Create a fresh pitch-shifted WAV

Select the source. Choose one browser-decodable audio file no larger than 50 MiB and wait for the tool to accept it.
Choose the semitone shift. Enter a whole-number value from -12 through +12. A value of 0 keeps the original pitch, +12 raises the material by one octave, and -12 lowers it by one octave.
Create the complete local render. The browser renders the full result at the decoded sample rate. The tool calculates the required output length before allocation and verifies the returned channel count, sample rate, and full frame count.
Review the stated duration change. Confirm that the reported length makes sense for the selected direction and size of the shift.
Download the PCM16 WAV. Save the completed file, then open it in a trusted local player for testing.

The pitch ratio follows twelve-tone equal temperament and is calculated as rate = 2^(n/12), where n is the semitone shift. McGill University’s MIDI/Frequency Conversion notes explain the twelve equal semitones in an octave and their frequency relationship. MDN’s playbackRate documentation also explains that rates below one slow the audio, rates above one speed it up, and a non-unit rate causes resampling. For a +12-semitone shift, substituting 12 into the formula gives 2^(12/12) = 2, so the audio runs at twice the original rate and lasts roughly half as long.

Selected shift	Playback rate	Duration effect	What to expect
+12	2×	Roughly half the original duration	One octave higher, faster, and shorter
Above 0 but below +12	Above 1×	Shorter	An upward shift with reduced length
0	1×	Unchanged duration	Original pitch retained in a newly encoded WAV
Above -12 but below 0	Below 1×	Longer	A downward shift with increased length
-12	0.5×	Roughly twice the original duration	One octave lower, slower, and longer

The exact resulting duration depends on the source and selected shift, so use the value stated by the tool rather than estimating from a time display.

Match render errors to their cause

Input validation and output validation are separate stages. A file can pass every source check and still exceed the budget created by a downward pitch shift.

Observed problem	What it means	Corrective action
File is larger than 50 MiB	The encoded input exceeds the file-size limit.	Shorten or re-export the source as a smaller file.
Unsupported type or failed decode	The browser cannot decode the file or its codec profile.	Use a current browser or export the audio in a common browser-decodable format.
Invalid decoded dimensions	Duration, channel count, or sample rate is outside the accepted ranges.	Bring the decoded file within five minutes, eight channels, and 8,000–192,000 Hz.
Decoded input exceeds the sample budget	The decoded source contains more than 30 million channel samples.	Shorten the source or reduce its decoded channel count before trying again.
Requested shift is over budget	The complete shifted output would exceed 30 million channel samples.	Use a shorter source or, if the target pitch allows, a less negative shift.
The browser cannot allocate the output	The browser cannot allocate the complete rendered result.	Reduce demand by shortening the source or choosing a shift that produces less output.

Lowering pitch increases the required number of output frames, which is why a valid source can fail only after a negative shift is selected. The over-budget response explicitly means that nothing was truncated. The tool has no hidden duration cap and never substitutes an incomplete file for a failed render.

The page intentionally provides no in-page audio preview, so the absence of a preview is not a decoding error. Download the WAV and play that file in a trusted local player.

Inspect the downloaded file for genuine output problems

Once a WAV has downloaded, check the result rather than troubleshooting it through the source again.

Confirm that the perceived pitch moved in the selected direction and by roughly the expected musical interval.
Compare the duration with the tool’s stated result to verify that the timing change is consistent with playback-rate resampling.
Listen through the beginning and end to confirm that the complete render is present.
Check for harshness, distortion, aliasing, or clipping, especially after a strong upward shift.

Browser resampling quality is implementation-defined. Large upward shifts can expose aliasing or source-codec artifacts that were less obvious in the original. A smaller upward shift may reduce the severity, but it does not guarantee a clean result. PCM16 conversion can also differ slightly from the decoded floating-point source because of quantization, while samples are clipped to the legal -1 through +1 interval before conversion.

The download is a newly encoded, uncompressed, interleaved, little-endian PCM16 file in a RIFF/WAVE container. It does not retain the original codec, compression quality, bitrate, tags, artwork, chapters, cue points, loop metadata, or other container metadata. Missing metadata is therefore an expected export limitation, not a failed pitch shift.

Know when a different production workflow is needed

The central limitation is deliberate: this tool does not preserve tempo, speech cadence, beat positions, or the exact original duration. If a production requires a pitch change while keeping length fixed, use a dedicated phase-vocoder or another time-stretching workflow rather than trying to solve the timing problem with a different semitone value.

For quick creative experiments, practice tracks, sound effects, and rough editing, the local workflow is suitable. It is not a transparent mastering process. To make future diagnosis easier, note the source format, file size, decoded duration, channel count, selected shift, and exact error message. That record immediately separates a source rejection from a shifted-output budget failure or an expected duration change.