Adjust audio volume online — free
Quick answer Raise or lower an entire clip by a fixed amount in decibels.
Boost or lower the whole clip by a fixed amount (dB). Prefer Normalize if you want a consistent peak level. 15MB max (Pro: 20MB).
Free to try · No signup required · Commercial use allowed · How we test · About VoxCraft
Adjust audio volume online for free with VoxCraft. Upload an MP3 or other audio file, set a gain between −12 and +12 dB, and download a louder or quieter copy — no install and no signup on the free tier. For automatic leveling across files, prefer the Normalize tool.
Volume here is measured in decibels. +6 dB doubles the signal's amplitude, and +10 dB is roughly what most people hear as twice as loud. A boost of 3–6 dB is often enough to rescue a quiet voice memo; going much beyond that risks distortion if the recording already has loud peaks.
If a boost makes the file sound harsh or crackly, the loudest parts are clipping. Lower the gain, or use Normalize, which calculates a safe gain for you and guards against clipping.
How it works
- Upload your file.
- Set gain from −12 dB to +12 dB.
- Apply and download.
Who uses this
Music under voice
Drop a bed a few dB so narration stays clear.
Quiet phone memo
Add a small boost before editing.
Tips for better results
- Large boosts can clip — if the result distorts, try a smaller gain or Normalize instead.
- After adjusting, you can still run Normalize for a consistent peak.
Frequently asked questions
How do I make an MP3 louder?
Upload the file, move the gain up (for example +6 dB) and apply. You download a louder copy; your original is untouched.
What's the difference vs Normalize?
Volume applies a fixed dB change. Normalize measures the file and chooses the gain for you.
How much can I boost?
Up to +12 dB in one pass. For a bigger change, apply it twice — but watch for distortion.
Why does it sound distorted after boosting?
The loudest parts exceeded the maximum level and clipped. Use a smaller gain or Normalize.
Can I make audio quieter?
Yes — set a negative gain, such as −6 dB, to turn a music bed down under narration.