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Free Loudness Range Checker: is your video too dynamic for phone speakers?

Choose a video or audio file and get its loudness range (LRA), measured the EBU R 128 way, with the integrated loudness, a chart of the loudness over time and the quietest and loudest stretches, so you can click and hear them. Then a plain verdict: very compressed, fine, wide or too dynamic for phone speakers. Everything runs in your browser: your file never leaves your device.

Updated · Built by Kevin Tabares, long-form YouTube editor at Umbrella Creators.

Check the loudness range of a video or audio file

Your file stays on your device. Nothing is uploaded: your browser reads the sound and measures it right here, in this tab.

How to use it

  1. Choose the file: your finished export to check what viewers will hear, or a rough mix while you edit (MP4, MOV, M4A, WAV, MP3, AIFF or WEBM, up to 60 minutes).
  2. Press Check the loudness range. Your browser reads the sound and measures it; on my computer, an hour of sound took 2 to 8 seconds.
  3. Read the range and the verdict, look at where the line dips and peaks on the chart, and click any stretch to hear it in the player.

When your browser supports it, the file is read piece by piece, so memory stays low on long files. From MP4, MOV and M4A files only the sound is read, so even a video export bigger than 2 GB works. MKV and WEBM videos, and WAV, AIFF, MP3, OGG and FLAC files, are read through in small pieces. Less common sound formats, or files your browser cannot read that way, are opened whole, up to 2 GB.

FAQ

What is loudness range (LRA)?
Loudness range, written LRA, is how much the loudness of a programme moves around over time, in loudness units (LU). It comes from the EBU: the measure is defined in EBU Tech 3342, and EBU R 128 says it may be used to evaluate the loudness variation of a programme (both read on October 21, 2026). It takes the loudness of every 3 second stretch, leaves out silence and quiet background, and measures the distance between the 10th and the 95th percentile, so a single loud bang or a fade at the end does not change it. The EBU also says it should not be confused with dynamic range or crest factor.
How does this checker measure it?
The way EBU Tech 3342 describes it. Your browser applies the K-weighting filter of ITU-R BS.1770 to every channel at the file's own sample rate and measures the short-term loudness (a 3 second window, as in EBU Tech 3341) every 0.1 seconds. Then it drops the windows under -70 LUFS, drops those more than 20 LU under the average of what is left, and gives the 95th percentile minus the 10th. The integrated loudness uses 400 ms blocks with the -70 LUFS and -10 LU gates of BS.1770. The quietest stretches are where the 3 second loudness stays under the 10th percentile, or within 1 LU of it, and the loudest where it stays over the 95th, or within 1 LU of it; passages less than 4 seconds apart count as one, and a stretch has to get at least 1 LU past the median. When the range is under 3 LU, a stretch has to stay at least 3 LU under or over the median instead, so a flat file lists nothing.
What is a good loudness range for a YouTube video?
My rule of thumb from editing, not a YouTube or EBU rule: under 3 LU is very compressed (normal for a narration or a talking video, flat for a music and effects mix), 3 to 8 LU sounds natural and stays clear on phone speakers, 8 to 12 LU is wide, so the quiet parts can get lost on a phone or in a noisy place, and over 12 LU is closer to a cinema mix: viewers will reach for the volume. Films can be much wider: the example in EBU Tech 3342 (read on October 21, 2026), the DVD of The Matrix, measures 25 LU.
How accurate is it?
I compared it with the ebur128 filter of FFmpeg on 75 files: the four test tones in table 1 of EBU Tech 3342, read on October 21, 2026 (the EBU expects 10, 5, 20 and 15 LU, plus or minus 1, and it reads 10.0, 5.0, 20.0 and 15.0), noise switching between two levels, a 5.1 file, real narration with music and a real talking-head video, up to an hour long, in WAV, AIFF, MP3, M4A, MP4, MOV, MKV, WEBM, OGG and FLAC. The loudness range was within 0.2 LU of FFmpeg and the integrated loudness within 0.1 LU. The biggest differences were on compressed files (AAC, MP3), which your browser and FFmpeg decode with different code.
Why does a short clip get a strange range?
Because it has too few 3 second windows. EBU R 128 does not recommend the loudness range for programmes shorter than one minute, and EBU Tech 3342 warns that very short programmes with silence at the start or end, or made of isolated phrases, can read misleadingly high (both read on October 21, 2026). The checker needs at least 10 seconds and tells you when a file is under a minute.
Does it upload my file?
No. Your browser reads the sound and measures it on your own device; the file never leaves this tab, and nothing is downloaded either.

Who made this

I'm Kevin Tabares. I've edited long-form YouTube videos since 2015 (1,277 videos and 152.2M+ views tracked on YT Jobs) for channels like Rex & Alexa, Puff and Mud. I built this so you can see in seconds whether the loudness of a video jumps around too much for phone speakers, and hear the exact stretches, without uploading anything. If you want an editor for your channel, get in touch.

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