SPX to ZIP Converter
Processing entirely on your device — large files may take a moment.
SPX is Speex voice audio in an Ogg container — the codec of old VoIP recorders and Asterisk phone systems. ZIP is the safest archive to share — no special software needed on the receiving end.
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 ZIP
| SPX | ZIP | |
|---|---|---|
| Compression | Lossy Speex (Ogg) | Deflate / store |
| Best for | Call recordings, phone systems | Universal sharing |
How to convert SPX to ZIP
- 1
Select your files
Select your SPX file — it never leaves your device.
- 2
Convert instantly
The engine packs the file, byte for byte, into a ZIP container — no re-encoding, no quality change.
- 3
Download results
Download the finished 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 ZIP format
ZIP (PKWARE, 1989) is the archive format the world agreed on: per-file Deflate compression (or plain store), a central directory that lets tools list and extract single files without touching the rest, and thirty-five years of universal support. Windows, macOS, Linux, phones and browsers all open ZIP natively.
Its compression ratio is middle-of-the-road next to 7z, and its encryption story is genuinely mixed: the classic ZipCrypto is broken, while AES-256 works only in tools that opted in. For maximum compatibility of everyday sharing, though, ZIP remains the only safe answer.
+Strengths
- ✓Opens natively on every platform
- ✓Random access: extract one file, skip the rest
- ✓Thirty-five years of tooling maturity
!Limitations
- −Weaker compression than 7Z/RAR
- −Classic encryption (ZipCrypto) is broken
- −No built-in recovery records
Why convert SPX to ZIP?
There is a concrete reason this conversion exists: Speech-only: music is unusable ZIP sidesteps that — Opens natively on every platform If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this SPX to ZIP 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 ZIP?
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 ZIP reduce audio quality?
If ZIP is lossless, the output contains everything the SPX file contains — no further loss is added. If ZIP 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.