Video conversion
Convert FLV to MP4
Updated Jul 2026
FLV is the old Flash Video format used by web video players before Flash was retired; MP4 is what phones, browsers, and editors expect today. To convert, open the FLV in a converter and export it as MP4. Doing this on your own computer means the video file never has to leave your machine.
- Extension
- .flv
- Type
- Video
- Typically
- Legacy web video
- Compression
- Lossy
- Extension
- .mp4
- Type
- Video
- Typically
- The universal video format
- Compression
- Lossy
Convert FLV to MP4 on your own computer. Nothing uploads.
How to convert FLV to MP4
- Open Morphjet and drag in the FLV files, or a whole folder of them, that you want to convert.
- Choose MP4 as the output format.
- Convert. The MP4s are saved right next to your FLV originals, and nothing is uploaded anywhere.
FLV vs MP4: what actually changes
| FLV | MP4 | |
|---|---|---|
| Opens everywhere | No, requires Flash Player or a legacy media app | Yes, plays natively on phones, browsers, and TVs |
| File size | Comparable, older codecs are less efficient | Comparable or smaller, modern compression |
| Quality | Lower, limited by older video codecs | Unchanged if the FLV already used modern video, otherwise a small loss from re-encoding |
| Editing and uploading support | Poor, most editors and platforms have dropped it | Broad, the default format almost everywhere |
| Streaming friendliness | No, built for a browser plugin that no longer exists | Yes, built for streaming and progressive playback |
When to convert, and when not to
Convert FLV to MP4 when you've found old Flash-era video, a downloaded clip, a lecture recording, an old home video, and want to actually play, edit, or upload it, since almost nothing opens FLV directly anymore.
If the FLV is your only copy of something you care about, hold onto it until you've confirmed the MP4 plays correctly, since re-encoding an already-compressed video can't bring back detail that was lost the first time.
Why not just use an online converter?
FLV files tend to turn up when someone is going through an old hard drive, a downloaded lecture, or archived home video, the kind of thing you don't necessarily want to hand to a random website just to make it playable again. An online converter means uploading that footage to a server you don't control. Converting on your own computer keeps the video, and whatever is in it, on your machine the whole time.
Questions
Does converting FLV to MP4 lose quality?
It depends on how the FLV was encoded. Some FLV files already contain modern video data, so converting to MP4 can be a fast, quality-preserving copy. Others use older codecs, which means the video has to be re-encoded, and that step adds a small amount of quality loss.
Why won't my FLV file play anymore?
FLV was built around Adobe Flash Player, which was retired in 2020. Browsers, phones, and most current media apps no longer include Flash support, so FLV files that used to play fine in a browser often won't open at all now.
Will the MP4 keep the same audio and video quality as the FLV?
The video and audio carry over as closely as the codecs allow. If a re-encode is needed, the MP4 will be very close to the original, with a loss that's usually not visible.
Can I convert a whole folder of old FLV files at once?
Yes. Point Morphjet at the folder and it converts every FLV file to MP4 in one pass, which is useful for clearing out an old archive.
Can I convert FLV to MP4 without uploading it anywhere?
Yes. Morphjet runs the conversion on your own computer, so the file never goes over the internet. You can disconnect from wifi and it still works.
Morphjet converts FLV, MP4, and 1,800+ other formats, all on your machine. Launching this July.