Free Windows app - FFmpeg + libopus

X Opus Converter

A free Windows GUI for batch-encoding audio to the Opus format. Drag in MP3, FLAC, WAV, M4A, AAC, OGG or any audio FFmpeg can decode and get reference-quality Opus output with full encoder control - VBR/CVBR/CBR, application modes, complexity, EBU R128 loudness normalization and metadata preservation.

libopus VBR / CVBR / CBR EBU R128 normalize Album art passthrough Drag & drop Multithreaded queue Filename templates Windows 10/11
Download X Opus Converter Free - Windows 10/11 - v1.0 - .exe - requires FFmpeg
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Release notes

What's new in v1.0

New
Initial public release

First public release of X Opus Converter. Batch queue with multithreaded encoding, drag-and-drop file/folder support, full libopus parameter control, EBU R128 loudness normalization, metadata and album art passthrough, and a colour-coded log tab for diagnostics.

What it does

Features

Multithreaded batch queue

Drag-drop individual files or whole folders. Encode 1 to 16 files in parallel - match your CPU core count and saturate the machine.

Full Opus encoder control

VBR (recommended), CVBR (constrained for streaming), CBR (hard). Application modes: audio, voip, lowdelay. Complexity 0-10. Bitrate 6-510 kbps.

EBU R128 loudness normalization

Normalize every output file to a target LUFS level - broadcast (-23), streaming (-16) or modern loud (-14). Consistent playback volume across your library.

Metadata and album art preserved

ID3 and Vorbis tags (artist, album, title, year, genre, track number) carried through automatically. Embedded cover art passes through as attached_pic.

Filename templates

Tokens for {artist}, {album}, {title}, {tracknumber}, {date}, {genre}. Mirror source folder structure or flatten into a single output folder.

Live log + diagnostics

Colour-coded log with timestamps. Per-file progress. Verbose mode captures every line of FFmpeg output for troubleshooting failed encodes.

Portable - no installer

Single 12 MB .exe. Settings stored in your user profile. No registry writes, no system services, no spyware, no ads, no nag screens.

X Opus Converter - free Windows GUI showing the encode tab with file queue, output folder and Opus encoder settings

X Opus Converter v1.0 - Windows 10/11

Requirements

What you need to download

X Opus Converter is a GUI front-end and does not bundle FFmpeg itself - this keeps the download small and lets you use whichever build you already have. Place the executables in the same folder as X Opus Converter.

Required

FFmpeg (with libopus)

Required for all encoding. Download a static Windows build from free-codecs.com - it includes libopus, every input decoder you need, and ships as a single self-contained .exe with no DLL dependencies.

Download FFmpeg
Recommended

FFprobe

Improves source duration detection and metadata reading. Usually included in the same FFmpeg .zip - just drop ffprobe.exe next to ffmpeg.exe. The tool falls back to ffmpeg-only probing if ffprobe is missing.

Also useful

X Audio Codec Pack (Opus playback)

After encoding, play your .opus files in any DirectShow-based player (MPC-HC, Windows Media Player, etc.) without extra hassle. Modern Windows 10/11, VLC, foobar2000 and browsers play Opus natively - this is only needed for legacy DirectShow setups.

Get X Audio Codec Pack
Which Opus mode should I use?

VBR vs CVBR vs CBR - and audio vs voip

Mode Quality File size Best for
VBR audio Best Variable Music library, ripping CDs / FLACs
CVBR audio Very good Mostly stable Streaming, podcast distribution
CBR audio Good Predictable Live broadcast, fixed-bitrate channels
VBR voip Speech-tuned Tiny Podcasts, audiobooks, voice memos
CBR lowdelay Good Predictable Live calls, real-time streams

Recommended bitrates: 96 kbps VBR audio for music (near-transparent), 128 kbps for archival, 32-48 kbps voip for speech. Opus is more efficient than MP3 or AAC at every bitrate, especially below 96 kbps.

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FAQ

Frequently asked questions

Why doesn't X Opus Converter include FFmpeg?
Bundling FFmpeg would add ~80 MB to the download. By keeping it separate you can use any FFmpeg version you already have, update it independently, and X Opus Converter stays portable at ~12 MB. FFmpeg is a free download from free-codecs.com.
What input formats are supported?
Anything FFmpeg can decode. That includes lossy formats (MP3, AAC, M4A, OGG Vorbis, Opus, WMA), lossless formats (FLAC, WAV, AIFF, ALAC, APE, WavPack), and video containers (MP4, MKV, WebM, AVI, MOV, TS, MKA) where the audio track is extracted automatically.
How do I convert MP3 to Opus on Windows?
Drop your MP3 files into the queue, pick an output folder in the encode tab, and click Start encoding. The default settings (96 kbps VBR, audio mode, complexity 10) produce near-transparent music. The tool calls FFmpeg with libopus underneath, so the output is identical to the reference opusenc encoder.
What bitrate should I use for Opus?
For music: 96 kbps VBR is near-transparent and is the recommended default. 128 kbps for high-quality archival, 160-192 kbps if you want maximum headroom. For speech and podcasts: 32-48 kbps with the voip application mode is plenty. Opus is consistently more efficient than MP3 or AAC, especially below 96 kbps.
Does it preserve metadata and album art?
Yes. ID3 and Vorbis tags (artist, album, title, year, genre, track number) are preserved by default. Embedded album art is passed through as an attached_pic stream in the Opus file. Both can be disabled in the Options tab if you want a clean output.
What is EBU R128 loudness normalization?
EBU R128 is the broadcast loudness standard. X Opus Converter can normalize all output files to a target LUFS level so playback volume is consistent across your library. Targets: -23 LUFS (broadcast), -18 LUFS (middle ground), -16 LUFS (Spotify, YouTube), -14 LUFS (modern loud masters).
Why is Opus better than MP3 or AAC?
Opus is newer (2012), royalty-free, and combines low-latency speech coding (SILK) with high-quality music coding (CELT) in one codec. At equal file size it sounds noticeably better than MP3 and slightly better than AAC, especially below 96 kbps. It is the preferred codec for WebRTC, YouTube, WhatsApp, Discord and Zoom.
Where can I play Opus files?
Modern Windows 10/11 plays Opus natively in Movies & TV, Groove Music and any browser. VLC, MPC-HC, foobar2000, Winamp and MPV play it everywhere. Android plays Opus natively; iOS supports it in third-party apps and most browsers. For DirectShow-based players on legacy setups, install X Audio Codec Pack.
Can I convert FLAC to Opus without quality loss?
Opus is a lossy codec, so any encode reduces information regardless of source. That said, encoding FLAC at 128 kbps VBR Opus is transparent for almost all listeners and material - blind listening tests consistently show no audible difference at this rate. Keep your FLAC originals as a master archive and use Opus for portable playback.
Does X Opus Converter need an internet connection?
No. The tool is fully offline. The only network use would be following the in-app link to download FFmpeg if you do not already have it.
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