Free online AVIF to MP4 converter

What the AVIF format is

AVIF is an image format based on the AV1 video codec. It stores still images, and it can also store animated image sequences, usually with smaller files than JPEG or PNG at comparable visual quality. Phones, web browsers, screenshot tools, image editors, and export tools such as Photoshop, GIMP, and ImageMagick can create AVIF files. You commonly encounter .avif images downloaded from websites or exported by modern mobile and desktop software.

What the MP4 format is

MP4 is a multimedia container, normally using H.264 or H.265 video and optionally AAC audio. It is accepted by most video editors, phones, televisions, social platforms, and media players. An MP4 made from one still image contains repeated video frames for a selected duration; it has no audio unless you add an audio track.

How to convert AVIF to MP4

Using 101convert.com

On 101convert.com, select the AVIF-to-MP4 converter, upload the .avif file, set the output duration or other available video options, start the conversion, and download the resulting .mp4 file. This option requires no software installation.

Using FFmpeg

FFmpeg can turn a single AVIF image into a five-second H.264 video:

ffmpeg -loop 1 -i input.avif -t 5 -c:v libx264 -pix_fmt yuv420p -movflags +faststart output.mp4

Replace input.avif with the source filename and change -t 5 to the required duration in seconds. -loop 1 repeats the still image, libx264 produces broadly compatible video, yuv420p supports older playback devices, and +faststart moves MP4 metadata near the beginning for progressive playback.

If the source dimensions are odd and encoding fails, scale to even dimensions:

ffmpeg -loop 1 -i input.avif -t 5 -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -c:v libx264 -pix_fmt yuv420p -movflags +faststart output.mp4

For an animated AVIF, try processing its decoded frames directly:

ffmpeg -i animation.avif -c:v libx264 -pix_fmt yuv420p -movflags +faststart output.mp4

Animated AVIF support depends on the FFmpeg build and its AV1/AVIF libraries. If FFmpeg reports that the format or decoder is unavailable, use a current build with AVIF support or convert the animation to image frames first.

Quality, compatibility, and limitations

The conversion decodes AVIF and re-encodes the result as video, so it is not lossless when using H.264. A higher-quality encode can use -crf 18 or another CRF value; lower CRF values produce larger files and generally preserve more detail:

ffmpeg -loop 1 -i input.avif -t 5 -c:v libx264 -crf 18 -pix_fmt yuv420p -movflags +faststart output.mp4

AVIF may contain transparency, wide-gamut colors, or HDR metadata that ordinary H.264 MP4 playback does not preserve reliably. Transparent areas usually become opaque, and yuv420p can reduce fine color detail. For maximum compatibility, use H.264, even pixel dimensions, and a frame rate such as 30 fps.