SPX to XZ Converter
Processing entirely on your device — large files may take a moment.
Speex Voice Audio and XZ Compressed File exist for different jobs: SPX is Speex voice audio in an Ogg container — the codec of old VoIP recorders and Asterisk phone systems. Unpack XZ into ZIP/TAR for tools that cannot read LZMA2.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How SPX compares to XZ
| SPX | XZ | |
|---|---|---|
| Compression | Lossy Speex (Ogg) | LZMA2 |
| Best for | Call recordings, phone systems | Packages and releases |
How to convert SPX to XZ
- 1
Select your files
Select your SPX file.
- 2
Convert instantly
The file bytes are gzip-compressed in place — the same archive your server or build tool produces, made locally.
- 3
Download results
Download the .gz file — ready to upload, serve or attach.
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 XZ format
XZ wraps the LZMA2 algorithm: the best ratio of the common Unix compressors, which is why distribution packages and source releases pick it when bandwidth matters more than CPU.
Windows Explorer and many cross-platform tools cannot open it — unpacking to ZIP or TAR makes the payload portable.
+Strengths
- ✓Highest common ratio
- ✓Standard for Linux packages
- ✓Integrity checks built in
!Limitations
- −Memory-hungry at high settings
- −Sparse support outside Linux
Why convert SPX to XZ?
Converting makes sense where the strengths of XZ meet what SPX cannot give you. Highest common ratio Meanwhile Speech-only: music is unusable One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this SPX to XZ 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 XZ?
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.
Is there a size limit for archive conversion?
There is no upload cap because nothing is uploaded — the practical limit is your device memory. A few hundred megabytes of unpacked content works comfortably on a modern computer.
What about folders and directory structure?
The full directory tree is preserved: folders stay folders, and deep paths arrive exactly as they were packed in the SPX file.