AVI to FLV Converter
Processing entirely on your device — large files may take a moment.
AVI Video and Flash Video exist for different jobs: AVI is Microsoft’s classic video container from the 90s. Files are large by modern standards but old devices and software still produce them. Rescuing FLV recordings means converting them to MP4 before Flash compatibility disappears completely.
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 AVI compares to FLV
| AVI | FLV | |
|---|---|---|
| Compression | Legacy codecs (DivX/Xvid era) | VP6 / H.264 legacy |
| Quality | Capped by its era | Of its era |
| Compatibility | Legacy Windows tooling | Legacy players only |
| Best for | Reading old archives | Early web video archives |
How to convert AVI to FLV
- 1
Select your files
Drag & drop your AVI 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 AVI format
AVI (Microsoft, 1992) is one of the oldest video containers still encountered. It has no native understanding of modern features — variable frame rates, modern codecs, subtitles, chapters — and stores everything through a 32-bit indexing system that caps reliable file sizes around 2 GB (OpenDML extensions patched some of this). Most AVIs you meet today are DivX/Xvid-era rips or old capture-card output.
There is no reason to produce AVI today; the realistic task is converting old libraries into MP4, which typically cuts file size by half or more at equal or better quality.
+ Strengths
- ✓Opens in legacy Windows tooling
- ✓Simple structure, decades of player support
! Limitations
- −Obsolete: no modern codecs or features by design
- −Large overhead, ~2 GB practical ceiling
- −Codec zoo inside — playback is guesswork
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 AVI to FLV?
There is a concrete reason this conversion exists: Obsolete: no modern codecs or features by design FLV sidesteps that — Only relevant for early-web video archives If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this AVI 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 AVI 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.
Does converting AVI 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.
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 AVI file has multiple audio tracks, the first one is used.