Sample Rate Checker
Check an audio file's real sample rate and understand the frequency ceiling it imposes.
Convert with this tool
or choose a file from your device — it is processed in this tab and never uploaded
Accepted: MP3, WAV, FLAC, M4A/AAC, OGG, Opus, video files
Files stay on your device. There is no upload, no queue and no watermark, so a conversion works even with the network switched off after the page has loaded.
Supported formats & processing
| Accepted input | MP3, WAV, FLAC, M4A/AAC, OGG, Opus, video files |
|---|---|
| Produced output | An inspection report with a downloadable JSON file |
| Processing | Web Audio API + canvas + native JavaScript encoders |
| Upload required | No — the file is read locally and never transmitted |
How to use this tool
- Add the audio fileThe declared rate is read from the header.
- Read the measured rateThis comes from decoding the audio, so it reflects what the file really contains.
- Note the frequency ceilingHalf the sample rate is the highest frequency the file can hold.
- Check the channel countMono versus stereo also affects how the file was produced.
- Decide whether resampling is neededThe sample rate converter can change it if a target requires it.
About this tool
Sample rate sets the highest frequency a file can represent: half the rate, which is the Nyquist limit. So 44.1 kHz can store up to 22.05 kHz, 48 kHz up to 24 kHz, and 16 kHz only up to 8 kHz — which is why telephone audio sounds the way it does.
This checker reports the declared sample rate from the codec header and the measured rate from the decoded audio, along with the Nyquist ceiling in plain language. It is the fastest way to find out whether a file labelled as high quality is actually a low-rate recording that has been upsampled.
Features
- Declared sample rate from the codec header
- Measured sample rate from the decoded audio
- Nyquist frequency ceiling stated in plain language
- Channel count and bit depth alongside the rate
- Detects upsampled sources where the rate exceeds the content
- Downloadable JSON report
Frequently asked questions
How do I know whether a file has been upsampled?
The declared rate will be high but the content will stop well below the Nyquist ceiling. A spectrogram makes it obvious: an upsampled file shows a hard cut-off with empty space above it.
Does a higher sample rate sound better?
Not beyond the point where it captures everything audible. 44.1 kHz already covers the full range of human hearing for playback. Higher rates matter for recording and processing headroom, not for listening.
What sample rate is best for video work?
48 kHz. It is the standard for video and broadcast, and it avoids a resampling step in the editor.
Can a low sample rate be fixed?
Resampling to a higher rate makes the file compatible with a specification but cannot restore the frequencies that were never captured. The missing content is gone.