Audio Compressors Compared: Submind vs MP3Smaller & Audacity
Three different ways to shrink an audio file — compared on privacy, limits, sign-ups, and cost, using each tool’s own documentation.
Last updated: October 28, 2026
| Tool | Processing | Max file size | Sign-up | Cost |
|---|---|---|---|---|
| Submind audio compressor | On-device in the browser — files never leave your computer | Up to 2 GB, 10 hours per file | None | Free |
| MP3Smaller | Cloud servers — your file is uploaded to FileConverto | 150 MB (MP3 only) | None | Free |
| Audacity | Desktop app — fully offline, manual export settings | Limited only by your hardware | None | Free, open source |
Details are taken from each tool’s own website as of 28 October 2026 and can change without notice — verify with the vendor before making decisions based on them.
Which one should you choose?
Use Submind when you want to compress a private recording without uploading it. Five presets cover 32 to 320 kbps, the tool shows the estimated output size before you start, and files up to 2 GB work. Try it here.
MP3Smaller is a simple choice for a single MP3 under 150 MB. It offers bitrate presets and needs no account, but the file goes to its servers and the tool accepts MP3 only.
Audacity is the right choice when you need full control: choose the encoder, bitrate, sample rate, and channels on export. It works offline, but it requires a desktop install and more steps.
Frequently asked questions
Is Submind’s audio compressor really free?
Yes. There is no cost, no account, and no daily limit. The compressor re-encodes the file on your device with FFmpeg, so there is no upload and no per-file billing.
Do any of these compressors upload my audio?
MP3Smaller uploads the file to FileConverto’s servers and removes it after a few hours. Submind compresses in your browser, so the file never leaves your device. Audacity is a desktop application that works entirely offline.
Which compressor supports the largest files?
Submind accepts files up to 2 GB and 10 hours. MP3Smaller accepts MP3 files up to 150 MB. Audacity has no fixed limit — it depends on your computer’s memory.
Does compressing audio reduce quality?
Yes. Compression to MP3 is lossy, so a lower bitrate means a smaller file and a higher chance of audible artifacts. Use 128 kbps for speech, 192 kbps for general listening, and 320 kbps for music you want to keep.