Does X (Twitter) support MP4 files?
a widely supported video container; acceptance also depends on the video and audio codecs inside it
X (Twitter) lists MP4 as one of its documented upload formats.
X (Twitter) accepts MP4 through its standard upload path. Check the platform's current help for any surface-specific rules (Reels vs Feed, Stories vs Posts, etc.).
Source: Koldflux Media Lab (engine-composed from the X (Twitter) platform constraint registry). Engine-derived answer; cross-check the platform's current help for surface-specific rules.
Frequently asked
Does X (Twitter) support MP4?
X (Twitter) lists MP4 as one of its documented upload formats. X (Twitter) accepts MP4 through its standard upload path. Check the platform's current help for any surface-specific rules (Reels vs Feed, Stories vs Posts, etc.).
How do I check whether my MP4 file will upload cleanly to X (Twitter)?
Open the Koldflux File Doctor, drop in the file, and pick X (Twitter). It reads the container, codec, resolution, duration and file size locally and reports pass / warn / fail against the documented X (Twitter) constraints.
Koldflux exports every clip in the format each platform actually wants - no compatibility guesswork, no manual conversion step.
Automate this in Koldflux