mp4 to flv Converter
Convert MP4 video clips into FLV animations or files locally in your browser. Absolutely secure—no files are uploaded to any server.
Select video source & options
Upload a .mp4 video or paste a URL, then configure your conversion parameters.
Import Video
Select a local MP4 file or paste a direct video link. The file size is processed fully locally.
Customize Parameters
Set starting time, output resolution width, and frame rates. Cap duration to optimize performance.
Download Result
FFmpeg converts frames locally into the selected FLV format for instant saving.
About the Conversion
MP4 to FLV Conversion
This tool converts MP4 (MPEG-4 Part 14) files to FLV (Flash Video) format fully in your browser. The most widely supported digital multimedia container. It offers an excellent balance of high compression efficiency and high visual quality across almost all platforms, operating systems, and devices. By converting to FLV, you take advantage of outputs a legacy flash video file for older archive and playback workflows.
Privacy-First Processing
Unlike traditional online converters that upload your media files to third-party servers, this converter runs 100% locally in your browser using WebAssembly technology. Your files are never exposed, sent over the network, or saved elsewhere.
Source format
What is MP4?
MP4 is a multimedia container that can hold video, audio, subtitles, and metadata in one broadly compatible file.
Advantages
- Plays on nearly every modern device, browser, and social platform.
- Offers a strong balance of video quality and file size.
Limitations
- Quality can be reduced when a video is re-encoded with lossy codecs.
- Its codec and container options are less flexible than formats such as MKV.
Output format
What is FLV?
FLV is a legacy Flash Video container that was commonly used for online video before HTML5 video became standard.
Advantages
- Useful for preserving or extracting video from older Flash-era archives.
- Can be compact for older web delivery workflows.
Limitations
- Modern browsers no longer support Flash playback.
- It has limited compatibility with current devices, editors, and platforms.
Help improve this converter
Real user feedback will appear here as it is collected. Share what worked, what did not, and the browser or stream type you used so the tool can become more reliable.
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