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Convert AVI video files to FLV for Flash-based video platforms, legacy streaming systems, and RTMP workflows. ChangeThisFile processes your file with FFmpeg on secure servers — no setup required.
By ChangeThisFile Team · Last updated: March 2026
ChangeThisFile converts AVI to FLV using FFmpeg, a professional-grade multimedia framework, to transcode AVI files to FLV format with optimized codec settings and quality preservation. Free with no signup required. Files are encrypted during transfer and automatically deleted from our servers after conversion.
AVI vs FLV: Format Comparison
Key differences between the two formats
| Feature | AVI | FLV |
|---|---|---|
| Full Name | Audio Video Interleave | Flash Video |
| Developer | Microsoft | Adobe Systems |
| Primary Use | Desktop video storage | Flash streaming and embedding |
| Video Codec | DivX, Xvid, H.264, MPEG-4 | H.263, VP6, H.264 |
| Audio Codec | MP3, PCM, AC-3 | MP3, AAC, Nellymoser |
| Streaming | Not optimized | RTMP, progressive download |
| Browser Support | No native support | Flash Player required |
| Modern Use | Archive/legacy | Legacy Flash platforms |
When to Convert
Common scenarios where this conversion is useful
Feeding a system that still requires FLV
If an older CMS, LMS, or RTMP server only accepts FLV uploads, convert your AVI file to satisfy that requirement. For anything modern, MP4 is the better target.
Matching an existing Flash-era archive
When a video library is already stored as FLV from the Flash era, convert new AVI files to FLV so the collection stays in one format. New archives should use MP4.
Older offline or embedded players
Some legacy desktop, kiosk, or embedded players were built around FLV and cannot read modern formats. Convert AVI to FLV only when you cannot update the player itself.
Who Uses This Conversion
Tailored guidance for different workflows
Content Creators
- Convert AVI footage to FLV for playback in software and devices that expect the FLV format
- Transform AVI recordings to FLV to match the format an existing workflow or player requires
Video Editors
- Convert AVI footage to FLV for importing into editing software like Premiere or DaVinci Resolve
- Transform AVI project exports to FLV for client delivery or final distribution
Social Media Managers
- Convert AVI videos to FLV for compatibility with legacy players or archival systems that use FLV
- Transform AVI source files to FLV when a specific tool only accepts FLV input
How to Convert AVI to FLV
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1
Upload Your AVI File
Select or drag and drop your AVI video. ChangeThisFile encrypts the upload in transit using HTTPS for your privacy and security.
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2
Server-Side FFmpeg Conversion
FFmpeg on our servers transcodes your AVI video and audio into the FLV container using H.264 video and AAC audio for Flash compatibility.
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3
Download the FLV File
Download your converted FLV when ready. The original AVI file is permanently deleted from our servers immediately after conversion.
Developers: convert via API →
Frequently Asked Questions
FLV is required for legacy Flash-based video platforms, RTMP streaming servers, and older embedded video players. Despite Flash's deprecation, FLV archives and some legacy systems still require this format.
Yes. VLC, MPC-HC, and many other media players support FLV playback without Adobe Flash Player, which was discontinued in 2020.
FFmpeg supports most AVI codec variants including DivX, Xvid, MPEG-4, H.264, and older codecs. Rare or proprietary codecs may not convert successfully.
The FLV output uses H.264 video encoding with AAC audio, which provides the best quality-to-size ratio for Flash-compatible video.
Files up to 25MB (free tier; 100MB with eligible paid browser access) are supported. Trim or compress your AVI if the file is larger.
All uploads use HTTPS encryption. Files are automatically deleted from our servers after your download completes — no retention, no sharing.
Most AVI to FLV conversions take 30-90 seconds. Larger files may take a bit longer depending on server load.
Yes. FFmpeg re-encodes the AVI audio as AAC in the FLV container. Common audio codecs in AVI (MP3, PCM, AC-3) are all supported.
Yes, FLV with H.264 encoding supports HD up to 1080p. The output resolution matches your source AVI.
Yes. ChangeThisFile is completely free — no accounts, no subscriptions, and no watermarks.
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Need to convert programmatically?
Use the ChangeThisFile API to convert AVI to FLV in your app or script. Free tier included.
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