✳ CODEC COMPATIBILITY
X (Twitter) AV1 in MP4
AV1 in MP4 is not in x's documented upload list. Convert before uploading.
Quality impact not documented · AV1 is not in X Media Studio list.
AV1 inside MP4 (with the av01 sample entry) is the modern open-codec upload pair. Not listed.
Choose a compatible conversion →ISO/IEC 14496-12 (ISO Base Media File Format) (verified 2026-09-18) · X Media Studio Library (verified 2026-09-18)
Frequently asked
Does X (Twitter) support AV1 in MP4?
AV1 in MP4 is not in x's documented upload list. Convert before uploading. Koldflux's compatibility engine reaches this verdict from sourced platform documentation.
Should I convert AV1 in MP4 for X (Twitter)?
AV1 inside MP4 is not the recommended upload for x; H264 inside MP4 is.
Will X (Twitter) re-encode my file?
AV1 is not in X Media Studio list.