Free tools for your next audio edit
Boost MP3 volume. Know the headroom.
Request a gain increase for a short MP3 or WAV and see how much fits under the sample-peak ceiling. Preview and download locally, without an account or audio upload.
Boost audio volume
Free · localChoose an MP3 or WAV. No account or audio upload required.
The same constant gain is applied to the whole recording and both channels. Background noise and existing distortion rise too; clipping is not repaired. The −1 dBFS limit is for decoded samples, not true peaks or LUFS. MP3 encoding may change the final peak. Input and output must each fit 50 MiB and five minutes.
Measure, boost, listen
How to boost MP3 volume online
- 01 / OPEN
Choose an MP3 or WAV
Select a mono or stereo file up to 50 MiB and five minutes. The browser decodes it locally and measures the largest absolute sample across both channels.
- 02 / SET
Choose a boost in decibels
Enter a positive gain up to 24 dB. The tool shows the amount it can apply while keeping the decoded sample peak at or below −1 dBFS; a loud source peak may limit the increase.
- 03 / LISTEN
Preview and download
Choose MP3 or WAV, create the file and listen at a low playback level first. Check the whole result and download the same file you previewed. Output must also fit 50 MiB and five minutes.
Understand the limit
Why might the applied boost be smaller than requested?
A constant gain raises every sample, including noise and the loudest transient. This tool limits the increase so the decoded PCM sample peak does not exceed −1 dBFS. For example, if a source peaks at −4 dBFS, approximately +3 dB of gain reaches the ceiling even if you request +6 dB. The preview shows both requested and applied gain.
If the source already peaks at or above −1 dBFS, this tool cannot apply a positive gain under that ceiling. A single loud transient can leave little headroom even when the rest sounds quiet. Silence has no nonzero signal to amplify. Gain does not repair clipping or make quiet and loud words more even.
Sample peak is not true peak or perceived loudness. MP3 re-encoding and playback reconstruction may produce higher peaks than the PCM samples used to set the gain. For a loudness target constrained by a sample-peak ceiling, compare the loudness normalizer; a target is not guaranteed to be reached. For dynamic range control, use a compressor in a suitable audio editor and compare the result with the original.
Check the actual export
Does boosting an MP3 improve its quality?
No. Boosting makes the decoded signal louder; it does not restore detail lost in the source, reduce hiss relative to speech or repair distortion. Background noise rises with the wanted sound. Listen to quieter and louder parts at a comfortable playback level.
MP3 output is a new lossy encode at the selected bitrate; the final decoded peak can differ and the file may include delay or padding. WAV is 48 kHz PCM16 and avoids another MP3 encode, but it does not recover missing detail. Browser decoding may resample the input; metadata, artwork and source bit depth are not copied.
If you want to select a desired sample-peak target instead of requesting a gain, use the peak audio normalizer. For an independent check of integrated loudness and sample peak in a supported file, use the loudness meter; it does not measure true peak.
MP3 encoder credits
Built with the LAME encoder via lamejs.
The optional MP3 download uses lamejs 1.2.1 by Alex Zhukov, a JavaScript port of the LAME MP3 encoder. Its unmodified script is served separately. See the attribution and source notes, upstream license notice, LGPL-3.0 and GPL-3.0 texts, and complete upstream source package.
A few useful answers
Free MP3 volume booster questions
How do I boost MP3 volume online?
Choose a supported MP3 or WAV, request a positive gain up to 24 dB, then preview and download MP3 or WAV. The applied gain is capped so decoded PCM samples do not exceed −1 dBFS. Input and output must each fit 50 MiB and five minutes.
Why was my boost limited?
A loud source sample leaves less headroom. The tool reduces the requested gain to keep the decoded sample peak at or below −1 dBFS and shows the applied amount. If the original is already at or above that peak, no positive boost is offered.
Will boosting remove noise or repair clipping?
No. Constant gain raises the entire recording, including noise and existing distortion. It cannot restore clipped samples or make quiet and loud passages more even.
Is the boosted MP3 lossless?
No. MP3 is decoded and newly encoded at the selected bitrate. Encoding can change the final decoded peak and add delay or padding. WAV avoids another MP3 encode but cannot restore missing source detail.
Is my audio uploaded?
No. The browser decodes, measures and boosts locally. Download the result before leaving; it is not saved for later.
Does the ceiling guarantee true peak or a loudness target?
No. The ceiling applies to decoded PCM samples before encoding; true peaks and integrated LUFS are not measured. MP3 encoding or playback reconstruction may produce higher peaks.
After preparing your audio