SPX vs WV
A detailed comparison of Speex Audio and WavPack Audio — file size, quality, compatibility, and which format to choose for your workflow.
📈 Target Minimum File Size (Guaranteed ≥ KB)
Lossless JPEG Q100 + standard COM segment padding for government & exam portals
Tap to choose your file Drop files here or click to browse
Automatic format identification and lossless transcoding across 201+ formats.
Convert to:
Detecting available formats...
Target Max File Size:
Uploading...
Processing your file...
READY!
Download File🛡️ Verification Audit
- ✓
- ✓ sRGB Color Fidelity
- ✓
Continue with this converted file (0s zero re-upload):
Need to convert larger files or bigger batches right now?
Unlock up to 1 GB & priority cloud queue with 1-click Stripe checkout (Apple Pay, Google Pay, Card):
Technical Specifications
| Specification | .SPX | .WV |
|---|---|---|
| MIME type | audio/speex | audio/x-wavpack |
| Extension | .spx | .wv (main), .wvc (correction) |
| Container | Ogg | — |
| Modes | Narrowband/Wideband/Ultra-wideband | Lossless, Hybrid lossy+correction, 32-bit float |
| Successor | Opus | — |
| License | — | BSD-style |
Strengths Comparison
.SPX Strengths
- Patent-free voice codec.
- Three sample-rate modes for voice.
- Low CPU decode.
.WV Strengths
- Hybrid lossy/lossless mode.
- Supports DSD, 32-bit float, multichannel.
- Competitive compression vs FLAC.
- Active maintenance since 1998.
Limitations
.SPX — Limitations
- Deprecated in favor of Opus.
- No music support.
- Rarely used in new projects.
.WV — Limitations
- Small ecosystem.
- Hybrid mode complexity.
- Hardware support limited vs FLAC.
Frequently Asked Questions
SPX (Speex Audio) is an audio file format used to store sound recordings — music, voice, podcasts, sound effects. The format defines how the audio samples are compressed (or stored raw), what bitrates are supported, and how metadata such as title, artist, album, and cover art is embedded. It is part of the audio files family.
WV (WavPack Audio) is an audio file format used to store sound recordings — music, voice, podcasts, sound effects. The format defines how the audio samples are compressed (or stored raw), what bitrates are supported, and how metadata such as title, artist, album, and cover art is embedded. It is part of the audio files family.
VLC, foobar2000, and the default media players on Windows and macOS handle SPX natively. On mobile, iOS Music and Android media apps vary in their support — popular formats work everywhere; niche ones may need a dedicated app. If playback fails on a device, converting to MP3 or AAC usually solves it.
VLC, foobar2000, and the default media players on Windows and macOS handle WV natively. On mobile, iOS Music and Android media apps vary in their support — popular formats work everywhere; niche ones may need a dedicated app. If playback fails on a device, converting to MP3 or AAC usually solves it.
Upload the SPX to KaijuConverter and pick MP3, WAV, FLAC, AAC, OGG, or any other target. Our FFmpeg pipeline decodes the audio and re-encodes to the target format at sensible default bitrates (VBR ~190 kbps for music, 96 kbps for speech). Metadata and cover art travel with the audio where both formats support them.
SPX can be lossy or lossless depending on the specific variant. Lossy variants (smaller files) discard some audio detail during compression in ways tuned to be inaudible; lossless variants preserve every sample exactly but produce larger files. For distribution, lossy at high bitrate is standard; for archival, lossless wins.
Need to Convert Gigabyte Archives or Mass Folders?
KaijuConverter delivers ultra-fast in-memory conversions for everyday tasks. For multi-gigabyte production workloads without browser bandwidth bottlenecks, explore high-throughput desktop suites.
One-time payment with zero recurring commitment: convert files up to 1 GB and 50-file batches for 24 hours.
Convert large videos, PDFs, and lossless audio directly in your browser—100% ad-free with priority queue.
High-throughput cloud pipeline for files up to 1,024 MB, 24-hour encrypted storage, and priority processing.
Convert thousands of camera RAW files (CR3, NEF, ARW) to WebP, AVIF, or TIFF in one pass.
GPU-accelerated RAW development with end-to-end 16-bit ICC color profile management.