Getting FLV onto a Mac
macOS has never supported FLV. QuickTime Player does not open it, iMovie and Final Cut Pro do not import it, and the Photos app ignores it. Since Flash Player was retired, a browser cannot show it either. MOV is the native QuickTime format, so to convert FLV to MOV is the simplest way to work with old Flash videos on Apple devices.
Typical cases:
- clips from an old website or a backup of a video portal that you want to reuse in an iMovie project,
- recordings of live streams that you want to edit in Final Cut Pro,
- old family or school videos that were saved as FLV and should play on an iPad.
Copy or re-encode
Later FLV files, and nearly all stream recordings, contain H.264 video and AAC sound. Those codecs are also standard in MOV, so the streams are copied into the new container. This takes only moments, even for long files, and nothing is lost. Earlier FLV files use Sorenson Spark or On2 VP6 video, often with MP3 or Nellymoser sound. These are re-encoded to H.264 and AAC, which every Apple device plays. The list shows the codecs of each file before you start.
Editing tips
Final Cut Pro and iMovie work best with a constant frame rate. Stream recordings sometimes have small timing jumps, which can cause audio drift in an editor. If you notice that, convert again with a fixed frame rate such as 30 fps. The video is then re-encoded with clean, even timing. Keep the original resolution: many old FLV clips are 480x360 or smaller, and making them bigger only increases the file size. iMovie can place small clips in a larger project without problems.
Other options
For files that will be shared with Windows and Android users too, FLV to MP4 gives the same quality in a more universal file. If a clip needs trimming or rotating after conversion, the MOV editor can do it. For the reverse direction, use MOV to FLV. The whole conversion happens in your browser, so your videos are not uploaded.