How to use
Drop an audio or video file, or click “Choose file”. The file is read in your browser and is not sent anywhere.
The format and bit depth, integrated loudness, LRA, true peak, peak, RMS and clipping are listed. Longer audio takes longer.
Change the silence threshold (dBFS) and the shortest length, and the list of silent sections updates at once.
Click a place in the waveform or spectrogram, or move the time slider, to read the values at that time.
Save the result as CSV or text, or copy it.
What it does
Same calculation as volume normalization
Integrated loudness, LRA and true peak use the same calculation functions as the volume normalization tool. Tests confirm that the same file gives the same values.
Levels and clipping
Shows peak, RMS and DC offset, and lists each run of full-scale samples with its time and length.
Silence and left-right correlation
Finds silent sections for a threshold and shortest length you set. For stereo, it computes the left-right correlation and flags a likely out-of-phase pair.
Read values at any time
Click a place in the waveform or spectrogram to read the RMS, peak and momentary loudness at that time.
Spectrum and spectrogram
Shows the average spectrum and a spectrogram of how frequencies change over time, with a colour legend.
Use cases
- Before publishing, check that integrated loudness and true peak sit within the range you need
- Find when and how often an export clips (hits the ceiling) and where it happens
- Find the silent sections at the start or end of a recording, to choose where to trim
- Check for out-of-phase left and right channels before listening in mono
Supported formats
Input
Capability matrix
| Feature | Support | Notes |
|---|---|---|
| Integrated loudness (LUFS) | Supported | ITU-R BS.1770-4, for audio with 1 or 2 channels |
| Loudness range (LRA) | Supported | EBU Tech 3342 |
| True peak (dBTP) | Supported | Approximated with 4x oversampling |
| Maximum short-term (3 s) and momentary (400 ms) loudness | Supported | — |
| Peak, RMS and DC offset | Supported | — |
| Clipping count and times | Supported | Three or more samples in a row at −0.001 dBFS or louder |
| Silent sections (threshold and shortest length you set) | Supported | Judged in 100 ms steps |
| Left-right correlation (likely out of phase) | Partial | Stereo only; judged over the whole clip |
| Waveform, spectrum and spectrogram | Supported | The spectrogram is an approximation of about 480 columns |
| Codec and bit depth | Partial | Bit depth is shown for PCM (such as WAV) only |
| Pass or fail against a delivery target (such as −14 LUFS) | Not supported | Shows the numbers only; does not judge pass or fail |
| Audio with 3 or more channels (such as 5.1) | Not supported | — |
| Video analysis | Not supported | Only the audio track is analysed |
| Judging sound quality, noise or distortion | Not supported | — |
| Changing the audio (volume or editing) | Not supported | Analysis only |
Limits & notes
- Up to 2 GB and 2 hours per file.
- Only the first audio track is analysed.
- Silence is judged in 100 ms steps; clipping needs three or more samples in a row.
- The spectrogram is an approximation of about 480 columns and 512 frequency bins.
Privacy & safety
Reading, analysis, the charts and saving all happen in your browser. Neither the file nor the results are sent to a server.
FAQ
What is LUFS?
Does it judge a delivery target such as −14 LUFS?
How is clipping counted?
What does a left-right correlation near −1 mean?
Are the values the same as in the volume normalization tool?
How is silence decided?
Related tools
Volume Normalization and LUFS
When sound is quiet, or the volume differs from file to file, set it to a target in LUFS. -14 suits YouTube and Spotify, -16 Apple Podcasts, and -23 broadcast. The tool measures first, then changes only the gain, and keeps the true peak under -1 dBTP. Your file is never uploaded.
Audio Editor
To cut unwanted parts of audio, drag on the waveform to select a range and press “Remove selected ranges”. To join clips, use “Join and edit” to set the order and any silence between them. You can save as WAV or MP3, or as M4A or Opus where your browser can write them. Your file is never uploaded.
Audio Converter and Video Audio Extractor
To get just the sound from a video, choose the video and an output format (MP3, M4A, WAV, Opus or FLAC). If the source audio is AAC, M4A is written without re-encoding, so the quality does not change. Your file is never uploaded.
Audio Noise Removal
To reduce background noise in a recording or meeting, choose the audio or video, set the strength and click “Remove noise”. Compare the result with the original, then save it as 16-bit WAV. Your file is never uploaded.
Music Tag Studio
Edit and save the tags of MP3 and FLAC files in one table. Title, artist, album, track number, year, genre, lyrics and album art are supported, and garbled Shift_JIS tags common in old Japanese MP3s can be re-read and saved as UTF-8 / UTF-16. Audio data is not changed by a single byte, and everything stays on your device.
Screen Recorder
Record a screen, window or tab, your webcam and microphone without installing anything. Add a camera overlay or mix mic and tab audio. Recordings stay inside this device and are never uploaded.
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