1Upload the MP3 audio files whose level you want to change.
2Set a gain in decibels or as a percentage — positive to boost, negative to bring it down.
3Run it; headroom is checked first, so a boost that would clip is flagged rather than silently squared off.
4Download the adjusted MP3 file.
Adjust MP3 Volume FAQ
Does the source format matter?
+
It does. MP3 is the universal lossy codec — nothing refuses to play it, at the cost of poorer quality per bit than AAC or Opus. That decides whether a gain change is an exact edit of the samples or has to go through a re-encode.
Anything specific to MP3 to know?
+
Yes — MP3 frames are fixed-size blocks, so a cut lands on a frame boundary and gapless playback markers do not survive a re-encode. Relevant if you plan to adjust the level more than once.
Should I use volume or normalisation?
+
Use volume when you know exactly how much louder or quieter you want it. Use normalisation when you want a set of files to end up at the same perceived loudness — that is a measurement problem, not a fixed gain, and applying one when you meant the other is the usual mistake.
Can I adjust a whole batch to the same gain?
+
Yes, though be careful what you are asking for: the same gain on files recorded at different levels keeps them at different levels. If you want them to match, normalise instead.
Can I run Adjust MP3 Volume on several MP3 audio files at once?
+
Yes. Upload the set and they process in parallel with the same settings, which is the practical way to handle a podcast series or an album rather than repeating the job by hand.
Do tags and cover art survive?
+
Yes. ID3, Vorbis comments and MP4 metadata atoms are carried across, cover art included, so a processed file still sorts correctly in a music library. ReplayGain values are recalculated rather than copied, because a stale one is worse than none.
Does Adjust MP3 Volume cost anything?
+
No. Adjust MP3 Volume is free without an account and adds no audio watermark or spoken tag to the output. Your upload is deleted from the workers shortly after the job completes.
Is there a file size limit on Adjust MP3 Volume?
+
Yes: free accounts process audio up to 200 MB per file, which at typical bitrates is several hours of material; ffmpeg does the decoding and encoding, exactly as it would on a desktop. That is the most generous cap on the site after video, and audio work rarely runs into it.
Why does a PNG site host Adjust MP3 Volume?
+
PNG.to is built around the format you use when you cannot afford to lose a pixel: lossless, alpha-capable, and the correct answer for screenshots, logos, line art and anything with hard edges. Image work is rarely one step: people arrive to change a format and leave needing the picture a different size, a different weight or a different shape. Running Adjust MP3 Volume on the same upload pipeline, the same size caps and the same account is the whole reason it is here rather than on a fourth tab.
What should I do with the result once Adjust MP3 Volume is finished?
+
The converter on this site moves images to and from PNG, JPG, WebP, GIF and SVG — which is the step where the decision about transparency actually gets made. That is the step most people actually came for, and doing it after Adjust MP3 Volume rather than before it means the conversion works from the file you finally settled on.
Is Adjust MP3 Volume here the same tool the sibling sites run?
+
The engines are shared — the same libraries, the same workers, the same limits. What differs is the advice, and the advice here starts from one fact about the format this site is named after: there is no quality slider to get wrong — a PNG round-trips bit-exactly, so the only thing edits cost you is file size. A PNG site is opinionated about where PNG is the right destination and where it is not, and that judgement is worth more than the button.
Do I need an account, and does anything get kept?
+
No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, and nothing you process is indexed, listed or used for anything else. Free accounts exist for history and batch size, not for access.
