Opus downloads

Even though Opus is now standardized by the IETF, this Opus implementation will keep improving in the future. Of course, all future versions will still be fully compliant with the Opus IETF specification.
See the development page for the latest development information.

Development binary builds

In addition to support in Firefox, Mozilla provides binary builds of Opus utilities.

• opus-tools 0.2
  (Opus 1.3)
  • Source
  • Windows
  • OS X (older)

Opus-tools provides command-line utilities to encode, inspect, and decode .opus files.

Source code (stable release)

• libopus 1.6.1

  Jan 14, 2026

  Opus 1.6.1 fixes several minor issues that were discovered since the 1.6 release.

  Source code: opus-1.6.1.tar.gz
  SHA256: 6ffcb593207be92584df15b32466ed64bbec99109f007c82205f0194572411a1

Source code (development releases)

• libopusenc 0.3

  Jan 3, 2026

  This release fixes a number of issues:

  • Fix ope_encoder_drain() assertion failures
  • Fix use of uninitialized fields
  • Fix undefined behaviour in picture.c
  • Fix crash with WIN32_LEAN_AND_MEAN on 64-bit Windows
  • Fix various warnings under C23
  • Drop use of private __opus_check_* macros
  • Port update_version from bash to sh
  • Clean up documentation files

  Source code: libopusenc-0.3.tar.gz
  SHA256: f616d3aff9b2034547894ccb8ab56c36cf1a4acb0d922c5d7119f97bbe58642c

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• opusfile 0.12

  Jun 27, 2020

  The opusfile library provides seeking, decode, and playback of Opus streams in the Ogg container (.opus files) including over http(s) on posix and windows systems.

  opusfile depends on libopus and libogg. The included opusurl library for http(s) access depends on opusfile and openssl.

  Changes since the v0.11 release:

  • Fix stack overflow buffering out-of-sequence streams.
  • Fix possible divide-by-zero.
  • Fix issues with seeking in the win32 backend.
  • Fix an issue where the seek algorithm could be confused by stream data changing between reads.
  • Clean up compiler and scan-build warnings.
  • Avoid use of the deprecated ftime() function which has Y2038 problems.
  • Remove undefined behaviour memcpy(NULL) in op_read_native().
  • Visual Studio project files updated for libogg 1.3.4 library name change.
  • Various build systems updates.
  • Various integration and testing environment improvements.

  This release is backward-compatible with the previous release. We recommend all users upgrade.

  Note that because of the removal of certificate store hooks in openssl 1.1.1 and later, there are unfortunately no supported versions of that library which can be used with the code in opusurl to validate https responses against the system certificate store on Windows. Using the system default access to the certificate store on other platforms works fine.

  Source code: opusfile-0.12.tar.gz, opusfile-0.12.zip.

  SHA-256 checksums:

  118d8601c12dd6a44f52423e68ca9083cc9f2bfe72da7a8c1acb22a80ae3550b  opusfile-0.12.tar.gz
  7f44575596b78d7787c1865b9653e2a71546ff1ae77d87c53ab16dcc7af295ba  opusfile-0.12.zip
  

  No Windows build is available for this release. Developers should integrate the source code directly into their applications.

  Programming documentation is available in tree and online.

  The library is functional, but there are likely issues we didn’t find in our own testing. Please give feedback in #opus on irc.libera.chat, opus@xiph.org, or at gitlab.

---

• opus-tools 0.2

  Sep 18, 2018

  In this release the Opus decoder opusdec has been converted to use the opusfile library, and the Opus encoder opusenc has been converted to use the libopusenc library. These libraries make it easy to robustly read and write Ogg Opus audio files, and enable some new features. Both libraries are available on the Downloads page.

  opusdec enhancements include:

  • Read directly from http or https sources
  • New option --force-stereo will force stereo output
  • Improved support for chained input files with differing sample rate or channel count
  • A summary is displayed for METADATA_BLOCK_PICTURE tags rather than displaying the base64-encoded data

  opusenc enhancements include:

  • Delayed decision support allows the encoder to look ahead up to two seconds in order to improve encoding decisions
  • The options --music and --speech can be used to tune low bitrate audio for music or speech, overriding automatic detection
  • The option --no-phase-inv disables the use of phase inversion for intensity stereo, which can be useful for streams that are likely to be downmixed to mono after decoding
  • New --tracknumber shortcut for setting tracknumber metadata

  Additionally:

  • The opusinfo utility can display the demixing matrix from Ogg Opus files using ambisonics channel mapping family 3
  • The experimental opusrtp tool supports new options to specify RTP payload type, Ogg Opus output file, original sample rate, and number of channels, and supports improved transmit timing, arbitrary network devices, and IPv6
  • The Visual Studio 2015 project builds opusenc support for FLAC input
  • The old Visual Studio 2010 project has been removed
  • Numerous bug fixes are also included

  Source code: opus-tools-0.2.tar.gz, Win32 binaries: opus-tools-0.2-win32.zip, Win64 binaries: opus-tools-0.2-win64.zip

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• libopus 1.3-rc2

  Sep 18, 2018

  This Opus 1.3-rc2 release candidate of the upcoming Opus 1.3 includes:

  • Fixing an issue with bandwidth detection
  • Enabling Ambisonics support by default
  • Using mapping families 2 and 3 for Ambisonics (instead of experimental families 253 and 254)
  • Enabling hardening by default

  Source code: opus-1.3-rc2.tar.gz

See the news archive for all releases