Speex（SPX）は音声通話向けに設計された圧縮形式です。人の声を低ビットレートで明瞭に伝えます。
Typical use: 通話録音を MP3/WAV に変換して保存・共有します。
About the SPX format
Speex（SPX）は人の声に特化した圧縮形式です。低ビットレートでも明瞭さを保ちます。
現在は Opus が後継です。古い録音を扱うには MP3/WAV への変換が便利です。
Strengths
- ✓ 声に強い
- ✓ オープンで無料
Limitations
- ✗ 現在は Opus が主流
- ✗ 音楽には不向き
- Compression
- Lossy Speex (Ogg)
- Quality
- Narrowband/wideband speech
- Compatibility
- Legacy VoIP stacks
- Best for
- Call recordings, phone systems
Convert SPX to…
27 direct directions plus 21 workflows, sorted A–Z; 🔥 marks popular targets.
Cross-engine workflows
Frequently asked questions
What is a SPX file?
SPX is Speex voice audio in an Ogg container — the codec of old VoIP recorders and Asterisk phone systems.
How do I convert SPX files online?
Pick a target format from the "Convert SPX to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert SPX files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can SPX convert to?
This page lists all 48 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.