Convert FLV to MP4 — Free Flash Video Converter
Convert FLV Flash videos to MP4 format. Rescue old Flash content for modern devices. Free online converter.
Conversion settings — add a file to adjust
About FLV files
FLV (Flash Video) was the standard web video format in the Flash era. Old site downloads, early streaming captures and archived web videos often come as FLV.
Flash is gone from browsers, and most phones and editors no longer open FLV. Converting to MP4 keeps these old videos watchable.
How we convert FLV to MP4
- Always re-encoded
- FLV is not in our copy-only set. The video is re-encoded to H.264 at CRF 23 and the sound to AAC at 192 kbps.
- Resolution
- Kept from the source. Old FLV files are often 480p or smaller, and we do not upscale them.
- Even dimensions
- Odd frame sizes, which some old FLV files have, are padded to even numbers so H.264 can encode them.
- Web playback
- The MP4 index sits at the start of the file.
Common problems and fixes
The MP4 still looks low resolution.
The FLV was probably recorded small. Conversion cannot add detail, so keep the original size to avoid a blurry upscale.
The FLV stops partway through.
Downloads from old sites are often incomplete. If the converter reports a corrupt file, get the video again from its source.
The sound is out of sync.
Some old live captures have broken timing in the FLV. Try trimming the start of the clip, then convert again.
About FLV to MP4 Conversion
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.
Why Convert FLV to MP4?
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.
Common Use Cases
- Rescue downloaded Flash videos from the pre-YouTube era