Free online HEVC to F4V converter

A legacy Flash-based application or publishing workflow may require F4V, while newer phones and cameras commonly create HEVC files. Converting normally requires transcoding to H.264 and AAC because F4V-compatible software generally does not decode HEVC.

What the HEVC format is

HEVC (High Efficiency Video Coding, also called H.265) is a video codec designed to deliver similar visual quality at lower bitrates than H.264. Phones, action cameras, mirrorless cameras, screen recorders, and video editors commonly create HEVC video, usually inside .mp4 or .mkv containers; a raw elementary stream may use .hevc.

HEVC is supported by current operating systems and media applications, but older browsers, Flash-based tools, and legacy hardware may reject it. The filename extension alone does not identify the codec, so inspect the stream with ffprobe input.mp4 when the source container is uncertain.

What the F4V format is

F4V is Adobe’s ISO Base Media Format-based Flash Video container. It was intended for Flash Player and Adobe media workflows and commonly stores H.264 video with AAC audio. Unlike older FLV files, F4V is based on the MP4 family of container formats.

F4V is useful only where a legacy Flash-compatible application or media server specifically requests it. Adobe ended Flash Player support, and modern browsers do not play Flash content, so F4V is generally unsuitable for current web publishing. It can still be required by archived projects, older e-learning systems, and discontinued broadcast or streaming pipelines.

How to convert HEVC to F4V

Using FFmpeg

Install FFmpeg, then open a terminal in the folder containing the source file. For HEVC inside an MP4 or MKV file, transcode the video to H.264 and the audio to AAC:

ffmpeg -i input.mp4 -map 0:v:0 -map 0:a? -c:v libx264 -crf 20 -preset medium -pix_fmt yuv420p -c:a aac -b:a 128k -movflags +faststart output.f4v

Replace input.mp4 with the actual source filename. The -crf 20 setting gives a high-quality variable bitrate result; values from 18 to 23 are a practical range, with lower values producing larger files. Use -preset slow for better compression at the cost of encoding time.

For a raw HEVC elementary stream with no audio, use:

ffmpeg -f hevc -i input.hevc -c:v libx264 -crf 20 -preset medium -pix_fmt yuv420p -an output.f4v

If the FFmpeg build does not select the F4V muxer automatically, specify it explicitly with -f f4v immediately before the output filename:

ffmpeg -i input.mp4 -c:v libx264 -pix_fmt yuv420p -c:a aac -f f4v output.f4v

Using the online converter

You can convert the file for free on 101convert.com without installing software: select the HEVC file, choose F4V as the output format, start the conversion, and download the resulting file. Avoid uploading confidential or restricted video to any online service.

Quality and compatibility limitations

This conversion is normally lossy: HEVC video must be decoded and re-encoded as H.264, so -c:v copy is not a reliable solution and may create an F4V file that the target player cannot decode. Keep the original HEVC file when it is needed as a master or archive.

Use -pix_fmt yuv420p for compatibility with older H.264/F4V decoders. Preserve the source resolution and frame rate unless the target system specifies limits. F4V support does not guarantee Flash playback on a current computer; test the result in the exact legacy application or playback environment that requires it.