Convert FLV Flash videos to MP4 format. Rescue old Flash content for modern devices. Free online converter.
Conversion settings — add a file to adjust
Upload your .flv file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .mp4 file when it's ready.
FLV (Flash Video) was once the backbone of online video—YouTube, Vimeo, and countless websites delivered content in Flash format. But Flash is now officially dead, and FLV files are digital fossils. Converting FLV to MP4 rescues your Flash videos for playback on modern devices that no longer support Flash.
Our FLV to MP4 converter handles all Flash Video variants, from ancient Sorenson Spark encoded files to newer H.264-in-FLV containers. Whether you're digitizing old video archives or recovering downloaded Flash content, the conversion produces clean, modern MP4 files.
Flash Player is discontinued and blocked by all major browsers. FLV files simply won't play on modern systems without specialized software. iOS never supported Flash. Android dropped support years ago. Converting to MP4 is necessary for these files to remain viewable.
Beyond playability, FLV conversion enables editing and sharing. Video editing software increasingly drops FLV import support. Social media platforms reject FLV uploads. Cloud storage services may not generate previews. MP4 solves all these issues.
Historical preservation matters too. Early web videos, Flash animations, and online content from the 2000s often exists only as FLV. Converting ensures this content survives for future viewing.
FLV files commonly contain Sorenson H.263, VP6, or H.264 video with MP3 or AAC audio. Our converter handles all variants. For H.264-in-FLV (common in later Flash era), we can remux without re-encoding for exact quality preservation.
For older Sorenson and VP6 codecs, we transcode to H.264 at CRF 18 for high quality. The decoder handles Flash-specific quirks including non-standard aspect ratios and unusual frame rates.
Conversion quality depends on the original FLV encoding. Early web videos were heavily compressed for 56k modems—we can't restore that lost quality. Newer FLV files, especially those with H.264, convert excellently.
| Device | FLV | MP4 |
|---|---|---|
| iPhone/iPad | No | Native |
| Android | No | Native |
| Windows PC | No | Native |
| Mac | No | Native |
| Smart TV | No | Native |
| Web Browser | No |
| Speed | ~6 seconds for a 10-second clip (FLV needs a real re-encode). |
| Output size | Similar to the source; FLV overhead is replaced by efficient MP4. |
| Quality | Re-encoded to H.264/AAC — modern, universally playable, unlike the legacy FLV. |
| Engine | FFmpeg (libx264), server-side. |
Measured on our servers, June 2026, on a 10-second 1280×720 clip.
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 High Profile, AAC audio
Resolution: 1080x1920
Bitrate: 3.5 Mbps
Vertical 9:16, max 90 seconds
Resolution: 960x540
Bitrate: 1-2 Mbps
Max 16MB, keep under 3 minutes
Resolution: 1080x1920
Bitrate: 4-6 Mbps
Vertical, max 10 minutes
Resolution: 1920x1080
Bitrate: 5-8 Mbps
Max 512MB, max 2:20 minutes
Resolution: 1280x720
Bitrate: 2-4 Mbps
Max 25MB free, 100MB Nitro
Don't let Flash's death orphan your video collection. Our FLV to MP4 converter breathes new life into Flash Video files, creating modern, playable videos from obsolete formats.
安全传输
HTTPS 加密上传
隐私优先
文件处理后自动删除
无需注册
即刻开始转换
随处可用
任何浏览器，任何设备
| Native |
| 特性 | FLV | MP4 |
|---|---|---|
| 全称 | Flash Video | MPEG-4 Part 14 |
| 扩展名 | .flv | .mp4 |
| 最适合 | Small file size | Universal compatibility |