Codex FFmpeg: the support and release mirror for gyan.dev's Windows FFmpeg builds

What Codex FFmpeg actually is, and who needs it

The README opens by calling this a support site for https://www.gyan.dev/ffmpeg, and the Releases section is described as a mirror for builds hosted at https://www.gyan.dev/ffmpeg/builds/. That framing matters more than the name suggests. There is no build system here, no patch set, and no FFmpeg source. The top-level repository entries are .github/ and README.md. If you came looking for an ffmpeg.exe inside the repository tree, it is not there; the binaries live at the gyan.dev URLs and the GitHub Releases page mirrors them.

The audience is narrow and specific. You are on Windows, you want a prebuilt FFmpeg rather than a compiler toolchain, and you want the build to be reproducible enough that an automated job can decide whether to download today. The README gives you the pieces for exactly that: single-line plain-text version files and SHA-256 files for the archives. A developer who just wants to run ffmpeg once from a terminal is not really the target. Someone maintaining a Windows CI image, a packaging script, or an internal mirror is.

The repository is not archived, and the last push was on 2026-09-28. The most recent release listed is 9.0.2 from 2026-09-20, following 9.0.1 on 2026-08-12 and 9.0 on 2026-08-04. Those release titles are written as "ffmpeg 9.0.2 builds", which is the clearest statement of what a Codex FFmpeg release contains: a set of builds corresponding to an upstream FFmpeg version.

The polling endpoints that make this repository useful

The README lists six URLs whose responses are single-line plain-text files, and instructs you to visit them and parse the result. They separate concerns that are usually tangled together: git-version, release-version, tools-version, last-build-update, next-build-update, and page-version. That is a deliberate design. A script that wants to know whether a new release build exists reads release-version. A script that wants to know whether the nightly git build has moved reads git-version. A scheduler that wants to avoid hammering the mirror reads last-build-update and next-build-update.

Because each file is one line, parsing is trivial in any language. There is no JSON schema to validate and no API key. The trade-off is equally plain: there is no versioned API contract documented in the README, so a change in the format of those files would break a naive parser. Treat the response as an opaque string to compare against your stored value rather than as a structured version to decompose.

The integrity side is separate. The README lists SHA-256 files for the main archives, including ffmpeg-git-full.7z, ffmpeg-git-essentials.7z, ffmpeg-release-full.7z, ffmpeg-release-essentials.7z, ffmpeg-release-essentials.zip, ffmpeg-release-full-shared.7z, and ffmpeg-tools.zip. The README states that all hashes are for the 7-zip archives unless the URL marks otherwise, which is why the .zip variant carries .zip in its hash filename. That distinction is the one detail most likely to trip up an automated check.

Getting the gyan.dev FFmpeg Windows build and verifying the download

There is no installer. The README points at the gyan.dev builds page and mirrors those archives in Releases, so the workflow is: read the version, download the archive, verify the hash, unpack, and put the binaries on PATH. The README gives no command-line examples at all; it only lists URLs and filenames. The blocks below therefore contain nothing but those URLs, exactly as the README writes them.

First, read the current release version so your script knows what it is about to pull. The README says to visit this URL and parse the single-line plain-text file received.

https://www.gyan.dev/ffmpeg/builds/release-version

Next, fetch the release essentials archive and its matching SHA-256 file. The README lists both URLs, and notes that all hashes are for the 7-zip archives unless the URL marks otherwise.

https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-essentials.7z
https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-essentials.7z.sha256

Compare the digest of the local archive with the value in the .sha256 file before you unpack anything. The README does not name a hashing utility, so use whichever one you already trust; the expected value is the contents of the file you just downloaded.

https://www.gyan.dev/ffmpeg/builds/ffmpeg-git-full.7z.sha256
https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-full.7z.sha256

If the two match, extract the archive and add the bin directory to PATH. The README does not document an extraction layout, so confirm the folder name after unpacking rather than assuming it. For a nightly instead of a release, the README lists git-version and ffmpeg-git-essentials.7z as the corresponding pair.

Where this mirror stops being the right tool

The README documents no rollback path. If a new build breaks your pipeline, nothing in the repository tells you how to return to the previous one, and the version endpoints only report the current state. You would have to keep your own copy of the last known-good archive and its hash. That is a real operational gap for anyone pinning builds in production, and it is worth designing around before the first bad update rather than after.

Platform is the second boundary. Everything the README describes is Windows-oriented: 7-zip and zip archives, an ffmpeg-tools.zip, and a builds page aimed at Windows users. If you need Linux or macOS binaries, this repository has nothing for you, and the SHA-256 files listed here will not help.

The third limitation is scope. Codex FFmpeg mirrors and verifies builds; it does not build them, patch them, or add codecs. If your requirement is a custom FFmpeg with specific codecs enabled or a particular licence configuration, a mirror of someone else's build flags is the wrong starting point. The README does mention that a resources section has been opened with a Codecs page at https://www.gyan.dev/ffmpeg/resources/codecs.html detailing all codecs in ffmpeg, which is useful for auditing what a given build contains, but that page describes builds rather than letting you change them.

Codex FFmpeg versus BtbN's ffmpeg-builds

The obvious alternative for Windows users is BtbN/ffmpeg-builds, which the related searches show people compare directly. The difference is in what each repository is. Codex FFmpeg is a support and mirror repository: the artifacts are produced and hosted at gyan.dev, and GitHub Releases duplicates them. BtbN's project is a build repository, where the release artifacts and the build automation live in the same place.

That distinction changes what you can inspect. With a build repository you can read the scripts that produced the binary and, in principle, reproduce or modify the build. With a mirror you can verify what you downloaded against a published hash, which is the guarantee Codex FFmpeg does offer through its .sha256 files, but you cannot see how the binary was assembled from the repository alone. If auditability of the build process matters more than the convenience of a stable mirror, the build-repository approach fits better. If you mainly want a predictable Windows binary plus a hash to check, the mirror is the simpler dependency.

Maintenance, releases and licence questions to settle yourself

The last push to the repository was on 2026-09-28, and the most recent release, 9.0.2, was published on 2026-09-20. Releases track upstream FFmpeg versions, with 9.0, 9.0.1 and 9.0.2 appearing within roughly seven weeks of each other. The practical upgrade cost is therefore driven by upstream FFmpeg's release cadence rather than by anything in this repository, and the version endpoints let you detect a new build without watching the Releases page by hand.

The licence situation is not stated in the README. The repository has no licence recorded, and the README does not name one. FFmpeg itself is distributed under the LGPL or GPL depending on how a given build is configured, and the README does not resolve which applies to which archive. The README does point to the Codecs page, which lists the codecs in ffmpeg and is the kind of page that usually accompanies build configuration details, but whether the licence terms of a specific archive are documented there is not something the README confirms. If you are redistributing these binaries, check the archive you actually ship and its accompanying documentation rather than assuming a licence from the repository name.

Editorial conclusion

Adopt Codex FFmpeg if you are on Windows and want gyan.dev's prebuilt FFmpeg binaries with a version endpoint and a published SHA-256 file you can check before unpacking. Do not adopt it if you need to build FFmpeg from source, need a Linux or macOS binary, or expect the repository itself to contain an ffmpeg.exe. Before you rely on it in a pipeline, fetch the version endpoints and confirm which one your update logic should track, and verify that the .sha256 file you download matches the archive name you actually pulled.

Frequently asked questions

Official sources

1. GyanD/codexffmpeg on GitHub
2. Issues
3. README
4. Releases