SPX to WV Converter
Processing entirely on your device — large files may take a moment.
Convert WV albums to FLAC for maximum compatibility. If your files are still in SPX format, this page is the shortcut: SPX is Speex voice audio in an Ogg container — the codec of old VoIP recorders and Asterisk phone systems.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How SPX compares to WV
| SPX | WV | |
|---|---|---|
| Compatibility | Legacy VoIP stacks | ffmpeg, WavPack CLI, fb2k |
| Best for | Call recordings, phone systems | Flexible archiving workflows |
How to convert SPX to WV
- 1
Select your files
Drag & drop your SPX files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to WV". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted WV file individually, or grab everything at once as a ZIP archive.
About the SPX format
SPX is Speex speech audio in an Ogg container — the open voice codec of the 2000s VoIP wave, tuned for telephone-band speech at absurdly low bitrates. Asterisk PBX call recordings and old conferencing archives are where you meet it.
Speex was formally retired in favor of Opus, and players have followed. Converting SPX to MP3 (or Opus for the adventurous) rescues call archives before they become unplayable.
+Strengths
- ✓Extremely compact for speech
- ✓Open-source lineage
!Limitations
- −Speech-only: music is unusable
- −Format officially retired
About the WV format
WavPack's signature trick is the hybrid mode: encode once into a small lossy .wv plus a tiny .wvc correction file — together they are bit-exact lossless, apart the small file plays like a high-quality MP3. It also offers pure lossless and pure lossy modes in the same container.
Full WavPack files decode losslessly through ffmpeg into FLAC or WAV; hybrid correction files are handled by the original encoder only, so a .wvc alone cannot be restored.
+Strengths
- ✓Unique hybrid lossy+correction mode
- ✓Fast decode, open source
- ✓Error-robust streaming modes
!Limitations
- −Ratios slightly behind APE
- −.wvc correction files are orphaned here
- −Hardware support rare
Why convert SPX to WV?
There is a concrete reason this conversion exists: Speech-only: music is unusable WV sidesteps that — Unique hybrid lossy+correction mode If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this SPX to WV converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for SPX to WV?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.
Will converting SPX to WV reduce audio quality?
If WV is lossless, the output contains everything the SPX file contains — no further loss is added. If WV is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.