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Free · No upload · No watermark · Gain or LUFS normalize

Change Audio Volume

Make an audio file louder or quieter — multipliers from 0.25× to 3×, output to MP3 / WAV / M4A / OGG / FLAC.

100% freeNo file size limitNo watermarkNo sign-up
  1. 1Pick file
  2. 2Configure
  3. 3Download
Gain multiplies the signal by a fixed factor (boost quiet audio or tame loud audio). Normalizebrings the file to a target loudness — −14 LUFS for streaming, −16 for podcasts, −23 for broadcast — regardless of how loud it started. That's the consistent-loudness feature paid tools charge for.
  • Files never leave your browser — processed entirely on your device
  • No upload, no queue, no waiting for a worker to free up
  • No file-size cap from us — limit is your device's RAM

About Change Audio Volume

AntiUpload's Change Audio Volume tool adjusts the loudness of an audio file by a fixed multiplier — 0.25× (quarter volume), 0.5× (half volume), 1.5× (50% louder), 2× (double volume), or 3× (triple volume). Useful when an interview, lecture, or voice memo was recorded too quietly to listen to comfortably, or when a track is too loud relative to other audio in a mixed playlist. Five output formats so you can convert format during the volume adjustment if needed — MP3, WAV, OGG, M4A, or FLAC.

We use FFmpeg's `volume=N` filter, the simplest and most predictable volume adjustment method. The signal gets multiplied by the selected factor; if the result would clip (exceed digital ceiling), it gets hard-clipped (which produces audible distortion on already-loud peaks). For quiet source there's plenty of headroom and 2× / 3× boosting works cleanly; for already-loud source the 3× setting may distort. The opposite (0.25× / 0.5×) reduces signal without artifacts. For broadcast-grade loudness normalisation (LUFS targets — streaming -14, podcast -16, broadcast -23), a future PR adds a separate loudness mode that does the two-pass measure-then-normalize workflow.

Compare to online competitors: AudioLouder, MP3Louder, OnlineMP3.org all upload your file to their servers (privacy concern for voice content), watermark/limit free tiers, and re-encode at potentially lower bitrate than your source. Ours runs entirely in your browser, no upload, no size cap, no watermark — and you control the output bitrate explicitly. Audacity (desktop, free) is the gold-standard alternative if you want non-browser. Ours is the browser-friendly version of Audacity's Amplify effect.

How it works

  1. Drop your audio fileAccepts MP3, WAV, M4A, OGG, FLAC, AAC, OPUS. No file-size limit — multi-hour podcasts work fine.
  2. Pick a volume multiplier0.25× / 0.5× to lower volume; 1.5× / 2× / 3× to boost. 2× is the typical "make this quiet recording listenable" choice. 0.5× tames overly-loud sources.
  3. Pick output format and bitrateKeep the input format (default) or convert during volume change. MP3 192 kbps balances quality and size for most uses. Pick FLAC / WAV if you want lossless re-encoding.
  4. Click Apply volumeRe-encoding completes in seconds for typical podcast / voice recordings. Long content (1+ hour audiobooks) takes proportionally longer.

When to use Change Audio Volume

Boosting a quietly-recorded interview / voice memo
iPhone Voice Memos / lecture recordings often peak around -20 dBFS — quiet relative to typical content. 2× or 3× boost brings them into normal listening range.
Levelling a music track for a quiet playlist
An album track that's louder than the rest of your playlist can be reduced (0.5×) to match. Or vice versa — boost the quiet songs in a mixed playlist for consistent listening level.
Reducing loud podcast intro music before sharing
Many podcasts have an intro music sting that's louder than the speaker's voice. Reduce overall volume before sharing if the intro feels disruptive. (For per-section volume change, trim into segments first with our Audio Trimmer.)
Boosting a hearing-impaired user's audiobook
Standard listening volume isn't enough for some users. Pre-boost the audiobook at 2× or 3× as a one-time conversion, then play at any volume on any device.
Reducing audio attached to videos before sharing on devices with limited speakers
Phone speakers are easily overwhelmed. A 0.5× volume reduction can make the same file more pleasant on a phone's built-in speakers vs headphones.

Frequently asked questions

How to make an MP3 louder online for free?
Drop your MP3 into AntiUpload Change Audio Volume, pick 2× or 3× multiplier, click Apply. No watermark, no upload, no size cap. Compare to AudioLouder (ad-heavy + limits), MP3Louder (older site, watermarks), OnlineMP3.org (paywalls).
What's the highest volume multiplier I can use?
3× is the cap. Higher would clip the digital signal (peaks exceed maximum, get hard-clipped to ceiling, produces audible distortion) on most real-world source. For truly quiet source where 3× still isn't enough, look at our (roadmapped) LUFS loudness normalisation mode which can boost more aggressively without clipping by also applying compression.
Will boosting cause distortion / clipping?
It depends on your source peaks. If source peaks at -10 dB, 3× brings the peak to -1 dB (loud but not clipped). If source already peaks at -3 dB, 3× clips (audible distortion). For loud source content stick to 1.5× max. For quiet source the boost is clean.
Best free audio volume booster?
AntiUpload Change Audio Volume — 5 output formats, no watermark, no signup, no size cap, no upload. Audacity (desktop, free, open-source) is the gold-standard alternative if you prefer non-browser. Online competitors all upload your audio and cap free tier.
Can I change volume of part of the file, not all of it?
Not in V1 — the volume multiplier applies to the entire file. For per-segment volume control, trim the file into segments with our Audio Trimmer, apply different multipliers, and join with Audio Joiner. A per-segment mode within this tool is on the roadmap.
Will this work on FLAC / WAV lossless files?
Yes. The volume filter applies in the audio sample domain (after decode), so it works regardless of source format. WAV in → WAV out is bit-perfectly clean (no generational loss). FLAC in → FLAC out is also lossless. MP3 / M4A / OGG go through a generational re-encode.
Why no LUFS loudness normalisation option?
LUFS-target normalisation requires a two-pass workflow (measure first, then encode against the measurement) plus a target picker (-14 / -16 / -23). It's a meaningfully different UX with different processing time. On the roadmap as a separate mode in this tool. For everyday "my audio is quiet" the gain mode handles it in one click.

Related tools

Audio TrimmerCut a clip out of an MP3, WAV, M4A, OGG, FLAC, AAC, or OPUS — fast and lossless, no re-encodeAudio JoinerCombine two or more audio files into one — pick MP3, WAV, M4A, OGG, or FLAC output, with optional crossfades or silence gaps between clipsExtract AudioPull the audio track out of any video — choose MP3, WAV, OGG, M4A, or FLAC. Quality presets, mono/stereo, optional VBR for lossy formatsChange Video VolumeMake a video louder or quieter — multipliers from 0.25× (whisper) to 3× (boost). Picture is stream-copied (no quality loss)