Best online audio converters (MP3, WAV, M4A, FLAC)
The best online audio converters in 2026 are FreeConvert, CloudConvert, Convertio and AudioToolKit. All four convert between MP3, WAV, M4A, FLAC and more in the browser. The difference is in limits: FreeConvert, CloudConvert and Convertio impose file-size and free-tier caps, while AudioToolKit runs in the browser with no install and files are deleted automatically.
How the online converters compare
All of these tools convert in the browser and all support the core formats. The practical differences are format breadth, how generous the free tier is, and whether large or frequent files hit a cap. LALAL.AI is included for reference, though it is a stem-separation tool rather than a general converter.
| Tool | Platform | Price | Best for | Notable limit |
|---|---|---|---|---|
| AudioToolKit | Web browser | Free | MP3/WAV/M4A/FLAC/OGG/AIFF in and out, 36 tools | No desktop app; basic tasks need no signup |
| FreeConvert | Web | Free tier + paid | Bulk conversion, many formats | File-size and monthly free-tier caps |
| CloudConvert | Web + API | Free tier + paid | Many formats, automation via API | Free-tier limits; account for large files |
| Convertio | Web | Free tier + paid | Quick online conversion | File-size and free-task limits |
| LALAL.AI | Web + desktop | Paid | AI stem separation (not a general converter) | Paid per-minute pricing |
Why AudioToolKit
If you want conversion with no install, no account for basic jobs and no server-side free-tier cap, AudioToolKit is one of the options here that fits. It supports MP3, WAV, M4A, FLAC, OGG and AIFF in and out, and deletes your files automatically:
- Audio converter — MP3, WAV, M4A, FLAC, OGG and AIFF, free in the browser.
- Video to audio — pull the audio track out of a video file.
- 432 Hz — retune a track to 432 Hz while you convert it.
What is the best free online audio converter?
For free, no-install conversion in the browser, AudioToolKit handles MP3, WAV, M4A, FLAC, OGG and AIFF with no account needed for basic tasks and files deleted automatically. FreeConvert, CloudConvert and Convertio are also strong, within their free-tier limits.
Can I convert MP3 to WAV online for free?
Yes. AudioToolKit's converter does MP3 to WAV in the browser for free, with no install and no account for basic conversions. FreeConvert, CloudConvert and Convertio also support MP3 to WAV, subject to their free-tier file-size limits.
What is the best online converter for M4A to MP3?
M4A to MP3 works in the browser with AudioToolKit, and is also supported by FreeConvert, CloudConvert and Convertio. Choose based on your file size, how often you convert, and whether you want no server-side caps.
Do online audio converters support FLAC?
Yes. AudioToolKit supports FLAC as both an input and an output format, so lossless conversion is available in the browser. FreeConvert, CloudConvert and Convertio also handle FLAC for online conversion.
What is the file size limit on free online converters?
It varies by service. FreeConvert, CloudConvert and Convertio cap free-tier file sizes and the number of free tasks per month. AudioToolKit processes in the browser and deletes files automatically, so server-side size caps are not the constraint.
Can I convert video to audio online?
Yes. AudioToolKit has a video to audio tool that extracts the audio track from a video file in the browser, so you can get MP3 or WAV from a video without installing software.