FLV to H.264 Converter
Processing entirely on your device — large files may take a moment.
Flash Video and H.264 Raw Video Bitstream exist for different jobs: FLV is the Flash-era video container from thousands of old video sites and screen recordings. Modern players have dropped it. Convert a .h264 dump to MP4 to add timestamps and player compatibility, or extract a raw H.264 stream from MP4 for pipeline use.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How FLV compares to H.264
| FLV | H.264 | |
|---|---|---|
| Compression | VP6 / H.264 legacy | H.264/AVC (lossy) |
| Best for | Early web video archives | Pipeline exchange, remuxing into MP4 |
How to convert FLV to H.264
- 1
Select your files
Drag & drop your FLV files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to H.264". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted H.264 file individually, or grab everything at once as a ZIP archive.
About the FLV format
FLV (Flash Video) was the video format of the early streaming web — YouTube's original delivery container from 2005 to ~2010, played by Adobe Flash Player. Later versions carried H.264/AAC, but the container lived and died with Flash, which reached end-of-life in 2020.
Modern browsers cannot play FLV at all, and only niche players (VLC) bother. If you have an FLV archive, converting to MP4 recovers the same H.264 video into a container every device accepts.
+Strengths
- ✓Only relevant for early-web video archives
!Limitations
- −Dead ecosystem — Flash ended in 2020
- −No browser support at all
About the H.264 format
H.264 (also called AVC) is the video codec the entire internet settled on: Blu-ray, YouTube, broadcast TV, every phone camera. A .h264 file is that codec's raw bitstream with no container — no timestamps, no audio, no metadata, just compressed frames back to back. Cameras and capture pipelines emit it because it is the codec's native shape.
Players struggle with raw streams precisely because there is no container to carry timing information. Wrapping H.264 into MP4 or MKV adds timestamps, duration and (optionally) audio tracks — the picture itself is untouched, since remuxing copies the compressed frames as-is.
+Strengths
- ✓The universal codec — plays everywhere once wrapped
- ✓Native output of cameras and capture cards
- ✓Remuxing is lossless (stream copy)
!Limitations
- −No container: no timestamps, no audio, no duration
- −Most players refuse or mis-time raw streams
Why convert FLV to H.264?
Think of it as moving your file to the container that fits the job. Dead ecosystem — Flash ended in 2020 H.264 works differently: The universal codec — plays everywhere once wrapped If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this FLV to H.264 converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for FLV to H.264?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Does converting FLV to H.264 re-encode my video?
Yes. The video is decoded and re-encoded with the settings chosen by the quality slider, which is what allows the format and size to change. For an archival copy, keep higher quality; for sharing, lower quality gives a much smaller file.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of H.264, staying in sync with the video. If your FLV file has multiple audio tracks, the first one is used.