FLV → MP4
Re-encodes Flash-era FLV courseware and web videos as H.264 + AAC MP4 with faststart — no Flash plugin needed on any platform.
Drag files here or click to upload (multiple files supported)
Ctrl+V to paste from clipboard
How to convert FLV to MP4
- 1Upload your FLV file by dragging, clicking, or pasting.
- 2Adjust quality settings if needed.
- 3Click 'Convert Now' and wait for the conversion to complete.
- 4Download your converted MP4 file.
About FLV to MP4 conversion
FLV is a container supporting RTMP streaming introduced by Macromedia in 2002. After Flash Player reached end of support in 2020, browsers no longer support this format. MP4 is a universal container for all platforms. The demand for FLV to MP4 conversion comes from legacy FLV files that cannot be played directly on modern devices.
This conversion is implemented based on FFmpeg. It retains the original H.264 video and MP3/AAC audio streams from FLV and encapsulates them directly into an MP4 container, without secondary transcoding, so no additional quality loss occurs. The output supports faststart for moving the moov atom to the file beginning, which is compatible with progressive playback.
This conversion is suitable for converting legacy FLV materials such as files downloaded from early video sites and recorded courseware into a format that can be played directly on Windows, macOS, mobile devices and all browsers, adapting to daily playback and secondary editing workflows.
FLV vs MP4: technical comparison
| Feature | FLV | MP4 |
|---|---|---|
| Released | 2002 | 2001 |
| Developer | Macromedia / Adobe | MPEG |
FAQ about FLV → MP4
Will quality be lost after conversion
If the original video and audio encoding of the FLV is compatible with MP4, the process is direct container remuxing without transcoding, so no additional quality loss occurs. If the encoding is incompatible, the file will be re-encoded according to the specified CRF parameter, and the quality is controlled by that parameter.
Will the original audio tracks be preserved
All audio tracks in the original FLV are preserved in the output MP4. FLV typically only encapsulates a single audio track, and the output MP4 retains all original audio track information completely, without arbitrary removal of tracks.
What is the maximum single file size
This service requires a maximum single file size of 50MB, and only one file can be converted at a time. The system will reject processing input files that exceed the size limit.
Will my files be stored
Files are uploaded to the server via HTTPS for conversion. After conversion completes, the server immediately deletes both the source file and the output file, and does not store any files, so user privacy is protected.