Convert FLV to MP4 Free Online — Flash Video to Modern Format
Convert FLV Flash Video to MP4 for playback on any device, browser, or platform. Video quality and audio are preserved.
Converting FLV to MP4 re-encodes the video into the MP4 container. Resolution and frame rate are preserved by default, and the audio track is copied without re-encoding when codec compatibility allows. File size depends on the chosen output codec.
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Checking files and selected output formats.
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Convert FLV Video in 3 Steps
Re-encode a video for broader playback support, easier editing, smaller files, or platform-specific upload requirements.
Drop your FLV video onto the tool or click to browse. Our converter handles all major codecs including H.264, H.265, VP8, and VP9 inside the FLV container.
Your video is re-encoded into the MP4 container with the optimal codec. Resolution and frame rate are maintained, and the audio track is preserved without re-encoding when possible.
Download your converted MP4 video ready for playback, editing, or uploading to any platform. Files are automatically deleted from our servers within 24 hours.
Why Convert FLV to MP4
MP4 with H.264 encoding is supported by virtually every phone, tablet, computer, smart TV, and game console manufactured in the last decade. No codec packs or special players needed.
H.264 in MP4 delivers excellent video quality at remarkably small file sizes. A two-hour HD movie typically fits in 1-2 GB, balancing quality and storage better than almost any other format.
MP4 supports progressive download and adaptive bitrate streaming out of the box. YouTube, Vimeo, Netflix, and every major streaming platform use MP4 as their primary delivery format.
Instagram, TikTok, Facebook, Twitter, and LinkedIn all recommend MP4 for video uploads. Using MP4 avoids server-side re-encoding that can reduce quality and delay your post.
MP4 containers can embed multiple subtitle tracks, chapter markers, and metadata. Viewers can switch between subtitle languages and jump to chapters without external files.
FLV vs MP4: Side-by-side
Technical comparison of the two formats — useful for deciding which to use, or for confirming what changes during conversion.
| Property | FLV | MP4 |
|---|---|---|
| Full name | Flash Video | MPEG-4 Part 14 |
| Year introduced | 2002 | 2001 |
| Developer / standard body | Adobe (formerly Macromedia) | MPEG |
| MIME type | video/x-flv | video/mp4 |
| File extension | .flv | .mp4 / .m4v |
| Compression | H.263, VP6, or H.264 | H.264 or H.265 codec |
| Color / data depth | 8-bit | 8/10-bit |
| Max dimensions / size | Codec-dependent | Codec-dependent (up to 8K) |
| Transparency | No | No |
| Animation | No | No |
| Standard / specification | Adobe (deprecated) | ISO/IEC 14496-14 |
| Best for | Legacy Adobe Flash video (deprecated 2020) | Universal video compatibility — plays on every device |
FLV to MP4 FAQ
Quick answers about compatibility, quality, metadata handling, and the most common reasons to convert FLV files to MP4.
How do I convert FLV to MP4 online?
What is FLV format?
Why convert FLV to MP4?
Will video quality be preserved?
Is FLV to MP4 conversion free?
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