MPEG4 to FLV Converter
Processing entirely on your device — large files may take a moment.
Rescuing FLV recordings means converting them to MP4 before Flash compatibility disappears completely. If your files are still in MPEG4 format, this page is the shortcut: MPEG4 is a common shorthand extension for MPEG-4 Part 2 streams — handled through the same MPEG program-stream path.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How MPEG4 compares to FLV
| MPEG4 | FLV | |
|---|---|---|
| Compression | MPEG-1 / MPEG-2 | VP6 / H.264 legacy |
| Quality | Standard definition | Of its era |
| Compatibility | Universal decode | Legacy players only |
| Best for | Legacy disc and capture video | Early web video archives |
How to convert MPEG4 to FLV
- 1
Select your files
Drag & drop your MPEG4 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 FLV". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted FLV file individually, or grab everything at once as a ZIP archive.
About the MPEG4 format
MPG (MPEG program stream) usually means MPEG-1 or MPEG-2 video — the codecs of VCD, SVCD and DVD, and of countless home video captures in the 1990s and 2000s. MPEG-1 tops out around VHS-grade 352×288; MPEG-2 delivers proper standard definition and still runs inside broadcast and DVD infrastructure.
Playback compatibility is its superpower: MPEG-1/2 decode paths exist in every player and hardware made this century. Quality-to-bitrate efficiency, however, is a generation behind H.264 — converting old MPG files to MP4 typically halves their size.
+Strengths
- ✓Decodes on essentially every player and device
- ✓Simple, battle-tested standard
!Limitations
- −Inefficient codecs by modern standards
- −MPEG-1 is VHS-grade at best
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
Why convert MPEG4 to FLV?
Converting makes sense where the strengths of FLV meet what MPEG4 cannot give you. Only relevant for early-web video archives Meanwhile Inefficient codecs by modern standards One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this MPEG4 to FLV 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 MPEG4 to FLV?
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.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of FLV, staying in sync with the video. If your MPEG4 file has multiple audio tracks, the first one is used.
Does converting MPEG4 to FLV 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.