Free Audio Converter Online: No Upload, No Sign-Up
Convert between MP3, WAV, FLAC, AAC, M4A, OGG, OPUS, WMA, AIFF, and WEBM. Set the bitrate, sample rate, and channels yourself or keep the defaults, then download the result. Conversion runs in your browser with FFmpeg, so nothing is uploaded and no account is needed.
Last updated: October 28, 2026
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First run downloads ~31MB engine · processing stays on your device
Usually takes 5–30s depending on file size
Weighing your options? Read how this tool compares with Convertio, CloudConvert, Zamzar and FreeConvert: audio converters compared.
Why Use Submind's Audio Converter?
Convert audio between formats with your files staying on your device.Private, On-Device
Your audio file never leaves your device. Nothing is uploaded to any server. Your recordings stay on your hardware.
Instant Conversion
FFmpeg runs directly in your browser using WebAssembly. There are no server queues or upload times, so results do not depend on your connection.
Free Forever
No subscription, no account, and no file size limits on our end. Free without registration or email collection.
Pro Audio Settings
Control bitrate (32-320 kbps), sample rate (8-48 kHz), and mono/stereo channels, comparable to desktop software.
10 Output Formats
Convert to MP3, WAV, FLAC, AAC, M4A, OGG, OPUS, WMA, AIFF, and WEBM with high-quality encoding and precision.
No Software Install
Works in Chrome, Firefox, Safari, and Edge. No downloads, no plugins, and no complex setup required.
Supported Audio Formats
The most common and professional audio formats supported on-device.MP3: MPEG Audio Layer III
The most universally supported audio format. Best for music, podcasts, and general playback. Use 128-192 kbps for general listening; 320 kbps for archival quality.
WAV: Waveform Audio
Uncompressed, lossless audio format. Best for audio editing and professional production where preserving perfect quality is essential before further processing.
FLAC: Free Lossless Audio Codec
Lossless compression that retains 100% of audio data at ~50% the size of WAV. Best for music archival and high-fidelity listening.
AAC: Advanced Audio Coding
The successor to MP3 with better quality at same bitrates. Native to Apple devices and standard for modern web streaming and video.
M4A: MPEG-4 Audio
Common for Apple voice memos and iTunes. Convert M4A to MP3 for universal compatibility, or to WAV/FLAC for professional editing.
OGG: Ogg Vorbis
Open-source format with excellent quality at low bitrates. Ideal for web streaming, gaming, and cross-platform open-source projects.
How to Convert Audio Files in 3 Steps
Change MP3, WAV, FLAC, AAC, M4A or OGG to another format at 32-320kbps. FFmpeg WASM runs in your browser, no upload.Choose Your Audio File
Select or drag and drop any audio file. Your file loads directly into your browser memory and stays on your device.
Set Output & Settings
Choose your target format and adjust bitrate or sample rate. Use 16kHz Mono for AI transcription optimization.
Convert and Download
Click Convert to process instantly using FFmpeg WASM. Download your new file without any server upload.
Audio Settings Guide
Master your audio conversions with the perfect settings.Bitrate: Quality vs Size
Bitrate determines the audio quality and file size for lossy formats like MP3.
| Bitrate | Best For |
|---|---|
| 128 kbps | Podcasts & Audiobooks |
| 192 kbps | Music (Standard) |
| 320 kbps | Archival Quality |
Sample Rate: Frequency
Sample rate affects the frequency range. Higher is better for music, lower for speech.
| Rate | Best For |
|---|---|
| 16,000 Hz | AI Speech Recognition |
| 44,100 Hz | CD Quality Music |
| 48,000 Hz | Professional Video |
Common Use Cases
Problem-solving audio conversion for every workflow.Speech-to-Text Prep
Convert any audio to 16,000 Hz Mono before transcribing to maximize AI accuracy for speech-to-text models.
iPhone Memo Conversion
Convert M4A voice memos to MP3 instantly for better compatibility with Windows PCs, Android devices, and video editors.
Reduce File Size
Compress massive WAV or FLAC recordings into high-quality 192kbps MP3s for easier sharing via email, Slack, or Telegram.
Car & Portable Players
Convert FLAC or M4A files to MP3 for a car stereo, an MP3 player, or any device that does not read the original format.
Editing Prep
Convert MP3 or AAC audio to WAV before you edit it in a tool that expects uncompressed audio.
Level Up Your Workflow
Turn your audio into notes with Submind AI
Record a thought and get a clean transcript, a structured note, and the action items.
Frequently Asked Questions
Common questions about our on-device audio converter.No. Submind uses FFmpeg WebAssembly (WASM) to process audio entirely in your browser. Your file stays on your device.