Upload an audio file and adjust bitrate, sample rate and channels. Output as MP3 or AAC (M4A). Free, no sign-up. Files auto-deleted after 15 minutes.
Drop your audio file here
or click to browse
This tool is for files you own or have permission to use.
This tool re-encodes your audio with the settings you choose. Use it to make files smaller for the web, match a platform’s spec, or export mono voice at a lower bitrate—while staying in MP3 or AAC (M4A).
Convert Audio Format is for switching between many container/codec pairs (e.g. WAV → FLAC, OGG → MP3). Change Audio Quality keeps you in the MP3 or AAC family and focuses on how strongly the file is compressed and how the PCM is sampled—bitrate, sample rate, and channel layout.
If you need ID3 tags or cover art on an MP3, use the main MP3 Toolbox flow after you have a file you are happy with.
You can start from MP3, WAV, FLAC, M4A, OGG, OPUS, or AIFF (as shown on this page). Maximum upload size is 100MB. Processed files are deleted automatically after about 15 minutes. See Privacy and Terms for details.
Bitrate is the main control for file size versus fidelity for lossy encodes. Lower values (e.g. 64–96 kbps) can be acceptable for speech or preview clips. 128 kbps is a common default for mixed listening. 192 kbps is a strong balance for music on phones and laptops. 256–320 kbps reduces artifacts further when you have complex music and enough storage.
For a deeper comparison of typical MP3 settings, read our MP3 bitrate guide.
Sample rate is how many times per second the audio is sampled. 44.1 kHz is standard for music CDs and most consumer audio. 48 kHz is common for video and many podcasts. 22.05 kHz or 16 kHz can shrink file size for voice-only content but rolls off high frequencies—fine for some talk tracks, less ideal for hi-hats and airy vocals.
Setting a higher sample rate on an already band-limited file does not add new treble; it only changes how the encoder resamples the source.
Mono duplicates a single channel—often roughly half the size of stereo at the same bitrate and works well for voiceovers, lectures, and some podcasts. Stereo keeps left/right separation for music and spatial effects. Choose mono only when you do not need a stereo image.
MP3 plays everywhere: old cars, cheap players, and broad tooling. AAC in M4A often gives better quality at a similar bitrate on modern phones and Apple-centric workflows. Pick the one your destination device or host recommends.
For server-side processing context, see How it works and the formats overview.
No. MP3 and AAC are lossy. Each encode discards information. Avoid many round-trips through lossy codecs if you care about long-term quality.
This page expects an audio file. To pull audio from video, use the home tool or video to MP3 first, then adjust quality if needed.
No sign-up is required.