WMA to Opus Converter

How to Convert WMA to Opus Online

1. Upload Your WMA File: Drag and drop or click "Add Files" to select your .wma audio. Standard WMA, WMA Pro, and WMA Voice variants are accepted. Batch uploads are supported, so you can re-encode an entire Windows Media library in one pass.
2. Pick a Quality Preset (or Custom Bitrate): Default is the Quality Preset dropdown (Highest, Very High, High, Medium, Low, Very Low). For finer control, switch to Constant Bitrate (32-384 kbps presets), Variable Bitrate (Opus VBR ranges from 6k-24k for voice up to 320k-510k for archival), Custom Bitrate (enter any kbps value), or Specific file size (target an exact MB/KB output).
3. Set Audio Channel and Sample Rate (Optional): Audio Channel dropdown offers Original, Mono, or Stereo — Mono roughly halves bitrate cost for podcasts and voice memos. Audio Sample Rate dropdown supports 8000-48000 Hz; Opus internally resamples to one of its five bandwidths (8/12/16/24/48 kHz), so 48000 Hz is the safe default for music.
4. Trim and Convert: Optional — toggle Trim on and enter Start Time and Duration in seconds or HH:MM:SS.sss format to extract a segment. Click "Convert" and download. Files are processed in your browser session with no watermark and no account required.

Why Convert WMA to Opus?

WMA (Windows Media Audio) is Microsoft's proprietary codec, released August 17, 1999 and tied closely to the Windows Media ecosystem. Opus is a royalty-free, open codec standardized by the IETF as RFC 6716 on September 10, 2012, jointly developed by the Xiph.Org Foundation and Skype (now Microsoft). Re-encoding a WMA library to Opus typically cuts file size 30-50% at equivalent perceptual quality, and unlocks playback on the modern devices and apps that ignored Microsoft's format.

• Massive low-bitrate gains for voice content — Opus at 32 kbps delivers wideband speech quality that WMA Standard cannot match below 64 kbps. The hybrid SILK/CELT architecture is why Discord, WhatsApp (1.5B+ users), and Zoom all picked Opus over WMA for real-time voice.
• Universal playback in modern browsers — Opus plays natively in Chrome 33+, Firefox 15+, Edge 14+, and Safari 18.4+ (iOS Safari fully supports it as of 18.4, partial in 11-18.3). WMA has zero native browser support — every <audio> tag with a .wma source fails. Caniuse reports ~96% global browser support for Opus.
• Android and Linux compatibility — Stock Android (Lollipop 5.0+) plays Opus in MP4/Matroska/WebM containers and as raw .opus. WMA support on Android requires third-party apps. Most Linux distributions ship Opus via the system audio stack but lack WMA decoders out of the box.
• Streaming and podcast distribution — YouTube serves audio in Opus, and many podcast hosts now accept .opus uploads to cut bandwidth costs. Re-encoding archived WMA shows to Opus at 64-96 kbps preserves intelligibility while halving CDN bills.
• Voice memos, language lessons, audiobooks — Spoken-word content at 24-48 kbps Opus is indistinguishable from the source for most listeners, while the same WMA file at that bitrate sounds muffled.
• Future-proofing a Windows Media library — Microsoft removed Windows Media Player from default Windows 11 installs in favor of the new Media Player app, and WMA's industry adoption has been declining for years. Opus, being open and patent-free, is a safer long-term archive format.

WMA vs Opus — Format Comparison

Opus Bitrate Cheat Sheet

Listening tests cited in the Opus reference comparison show Opus at 64 kbps rated superior to HE-AAC, and Opus at 96 kbps rated above AAC-LC, Vorbis, and MP3 at the same bitrate — WMA has not been competitive at these rates since the mid-2010s.

Frequently Asked Questions

What bitrate should I pick when converting WMA to Opus?

Match the content type rather than the source WMA bitrate. For spoken-word content (podcasts, audiobooks, voice memos) pick 32-64 kbps Opus — that's transparent to the human ear for speech. For music, 96-128 kbps Opus is roughly equivalent to a 192-256 kbps MP3 and indistinguishable from the WMA source for most listeners. Going above 192 kbps rarely improves perceived quality and is mostly useful for archival.

Will I lose audio quality going from WMA to Opus?

Both codecs are lossy, so any re-encode introduces generational loss. In practice the loss is small if you pick a sensible target bitrate — Opus is more efficient per bit than WMA, so even at a lower output bitrate the result usually sounds equivalent to the source. If the original WMA was very low bitrate (32-48 kbps), set Opus to 64 kbps or higher to avoid compounding artifacts. For lossless input, convert to FLAC instead.

Why pick Opus over MP3 or AAC for this conversion?

Opus beats both MP3 and AAC below ~128 kbps and is competitive at higher rates. It is royalty-free (MP3 was, AAC still has patents in some jurisdictions), plays natively in every modern browser, and was designed for both speech and music in the same codec. If you specifically need iPhone Music app compatibility or older car-stereo support, choose MP3 or AAC instead — see our WMA to MP3 or WMA to AAC tools.

Does Opus play on iPhone and iPad?

Yes, with caveats. Safari on iOS 18.4+ plays Opus natively in HTML5 <audio>. iOS 17+ added Opus support in the system AVFoundation framework, so most modern third-party apps (VLC, Infuse, Documents by Readdle) play .opus files. The default Apple Music app does not import .opus into a library — for that workflow, convert WMA to AAC instead.

Can I batch-convert an entire WMA folder?

Yes — drop multiple WMA files (or a folder of them) onto the uploader and each one is queued. The same Quality Preset, Channel, and Sample Rate settings apply to every file in the batch. Each finished Opus file is downloaded individually. For very large libraries, split into batches of 30-50 to keep browser memory steady.

Should I convert WMA Lossless to Opus?

If you have WMA Lossless masters, transcoding to lossy Opus discards data permanently — keep an archival copy in FLAC or ALAC first. Then convert a copy to Opus at 128-192 kbps for everyday listening. If you only have WMA Standard or WMA Pro to start with, going straight to Opus is fine.

What's the difference between Constant and Variable Bitrate for Opus?

Constant Bitrate (CBR) uses the same number of bits per second throughout the file — predictable file size, simpler for streaming buffers. Variable Bitrate (VBR) lets the encoder spend more bits on complex passages and fewer on silence, typically giving better quality at the same average bitrate. The Opus reference encoder defaults to VBR; pick CBR only when downstream tooling requires fixed-rate input.

Can I trim or split the file during conversion?

Yes. Toggle the Trim switch on, then enter a Start Time and Duration in seconds or HH:MM:SS.sss. Only the trimmed segment is encoded to Opus. For more advanced cutting (multiple segments, fade in/out), see the dedicated Audio Cutter tool. To go in the other direction, our Opus to MP3 and WMA to OGG tools cover related migrations.

Are my files uploaded to a server?

Files are processed via your browser session and not retained — they are not added to a public dataset, sold, or used for training. We process the conversion server-side so the codec stays consistent across devices, then immediately discard the input and output once you've downloaded the result. No account, no watermark, no email required.