Skip to main content
Video Conversion

Convert AVI to FLV — Free Online Converter

Convert Audio Video Interleave (.avi) to Flash Video (.flv) online for free. Fast, secure video conversion with no watermarks or registration....

nebo importovat z

2M+ souborů převedeno

Důvěřují tisíce uživatelů

Bezpečný přenos

Šifrované nahrávání přes HTTPS

Ochrana soukromí

Soubory automaticky smazány po zpracování

Bez registrace

Začněte převádět okamžitě

Funguje všude

Jakýkoli prohlížeč, jakékoli zařízení

Jak převést

1

Upload your .avi file by dragging it into the upload area or clicking to browse.

2

Choose your output settings. The default settings work great for most files.

3

Click Convert and download your .flv file when it's ready.

About AVI to FLV Conversion

AVI is a desktop-oriented container from the early 1990s with no built-in streaming capability. FLV (Flash Video) was Adobe's streaming video format, dominant across the web from 2005 to 2015, carrying Sorenson Spark (H.263), VP6, or H.264 video with MP3 or AAC audio. Although Flash Player reached end-of-life in December 2020, FLV files remain widely used in legacy content management systems, Chinese video platforms (Bilibili, Youku archives), and existing CDN workflows that have not migrated to MP4/HLS.

Why Convert AVI to FLV?

Some legacy systems and CMS platforms still require FLV format for video uploads. Older streaming servers (Red5, Wowza legacy configs) expect FLV input. If you manage a video library built on Flash-era infrastructure or need to deliver content to systems that specifically require FLV, converting AVI to FLV bridges the gap between desktop video and these legacy streaming workflows.

Common Use Cases

  • Uploading AVI files to legacy CMS platforms that accept only FLV
  • Converting AVI recordings for legacy Flash-based streaming servers (Red5, FMS)
  • Preparing AVI content for delivery to legacy Chinese video platforms using FLV
  • Migrating AVI archives into FLV for existing CDN workflows not yet updated to HLS/DASH
  • Creating FLV versions of AVI training videos for legacy e-learning systems built on Flash

How It Works

FFmpeg decodes the AVI video and audio streams, then re-encodes to H.264 (or Sorenson Spark for maximum legacy compatibility) for video and AAC (or MP3) for audio, wrapping the output in the FLV container. FLV supports H.264 at up to 1080p, but many legacy players expect lower resolutions (480p or 720p). The FLV container adds onMetaData tags (duration, dimensions, framerate, bitrate) for proper seeking in Flash-based players.

Quality & Performance

With H.264 encoding, FLV delivers quality identical to MP4 at the same bitrate and resolution — the container does not affect codec performance. If using legacy Sorenson Spark codec for older Flash Player compatibility, quality will be notably lower, comparable to early web video from the 2005–2008 era.

FFMPEG EngineModerateMinimal Quality Loss

Device Compatibility

DeviceAVIFLV
Windows PCNativePartial
macOSPartialPartial
iPhone/iPadPartialPartial
AndroidPartialPartial
LinuxPartialPartial
Web BrowserNoNo

Recommended Settings by Platform

YouTube

Resolution: 1920x1080

Bitrate: 8-12 Mbps

H.264 recommended for fast processing

Instagram

Resolution: 1080x1080

Bitrate: 3.5 Mbps

Square or 9:16 for Reels

TikTok

Resolution: 1080x1920

Bitrate: 4 Mbps

9:16 vertical, under 60s ideal

Twitter/X

Resolution: 1280x720

Bitrate: 5 Mbps

Under 140s, 512MB max

WhatsApp

Resolution: 960x540

Bitrate: 2 Mbps

16MB limit for standard, 64MB for document

Discord

Resolution: 1280x720

Bitrate: 4 Mbps

8MB free, 50MB Nitro

Tips for Best Results

  • 1Always include onMetaData at the beginning of the FLV file to enable proper seeking in players — FFmpeg's -flvflags add_keyframe_index parameter helps with this.
  • 2Use H.264 inside FLV instead of older Sorenson Spark unless you specifically need Flash Player 7 compatibility.
  • 3Consider converting to MP4 instead of FLV if your target system supports it — you get identical codec quality with better platform support.
  • 4Set keyframe interval to 2 seconds (GOP size of 2x framerate) for smooth seeking in streaming scenarios.

Related Conversions

AVI to FLV conversion serves a specific niche: feeding content into legacy Flash-era systems. For new projects, MP4 is always the better choice, but FLV conversion remains necessary for maintaining existing infrastructure.

Často kladené otázky

Marginally. Flash Player is dead, but FLV files persist in legacy CMS platforms, archived video libraries, and some Chinese streaming services. New projects should use MP4 instead.
H.264 (libx264) for the best quality and broadest compatibility with FLV-aware players. Sorenson Spark only if you must support Flash Player 7 or earlier.
Not natively. After Flash's deprecation, browsers cannot play FLV directly. You need a JavaScript-based player (like flv.js) or server-side transcoding to MP4/HLS.
FLV has limited subtitle support through onTextData events, but it is poorly standardized. For subtitled content, MP4 with WebVTT or SRT sidecar files is far more reliable.
FLV with H.264 codec technically supports up to 4K, but practical use is limited to 1080p. Most legacy FLV systems expect 480p or 720p content.

Related Conversions & Tools