Convert AVI to FLV Online Free

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

Quick Answer

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.

Free No signup required Encrypted transfer · Auto-deleted Under 2 minutes Updated March 2026

Convert AVI to FLV

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Drag & drop your .avi file here, or click to browse

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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

Legacy Flash CMS Upload

Convert AVI source files to FLV for upload to older Flash-based content management systems that expect FLV video input.

RTMP Broadcasting Archives

Prepare AVI recordings for streaming via RTMP server infrastructure or archiving alongside existing Flash Video libraries.

Flash-Based Website Players

Supply FLV content for legacy HTML pages with embedded Flash video players that do not accept AVI files.

Flash-Era E-Learning Content

Convert AVI training videos to FLV for upload to learning management systems built on Adobe Flash video delivery.

Archival Format Standardization

Convert AVI files to FLV to create a uniform Flash Video format archive across older media libraries.

Who Uses This Conversion

Tailored guidance for different workflows

Content Creators

Convert AVI footage to FLV for uploading to YouTube, TikTok, or social media platforms
Transform AVI screen recordings to FLV for sharing in blog posts or tutorials

Choose FLV at 1080p or higher for the best quality-to-size ratio on social platforms

Preview the converted FLV file before uploading to ensure audio sync is maintained

Video Editors

Convert AVI raw 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

Maintain the original resolution and frame rate during AVI to FLV conversion to avoid quality loss

Use a high bitrate when converting to FLV if the footage will undergo further editing

Social Media Managers

Convert AVI brand videos to FLV to meet platform-specific format requirements
Transform AVI ad creatives to FLV for cross-platform publishing campaigns

Check each platform's recommended FLV specs (resolution, bitrate, duration) before uploading

Keep the AVI original archived for future re-exports at different resolutions

How to Convert AVI to FLV

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.
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.
3

Download the FLV File

Download your converted FLV when ready. The original AVI file is permanently deleted from our servers immediately after conversion.

Frequently Asked Questions

Why convert AVI to FLV?

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.

Can I play FLV without Flash Player?

Yes. VLC, MPC-HC, and many other media players support FLV playback without Adobe Flash Player, which was discontinued in 2020.

What AVI codecs are supported?

FFmpeg supports most AVI codec variants including DivX, Xvid, MPEG-4, H.264, and older codecs. Rare or proprietary codecs may not convert successfully.

What video codec does the FLV output use?

The FLV output uses H.264 video encoding with AAC audio, which provides the best quality-to-size ratio for Flash-compatible video.

Is there a size limit on the AVI upload?

Files up to 25MB (free tier; 500MB on Pro) are supported. Trim or compress your AVI if the file is larger.

Is my file safe?

All uploads use HTTPS encryption. Files are automatically deleted from our servers after your download completes — no retention, no sharing.

How long will conversion take?

Most AVI to FLV conversions take 30-90 seconds. Larger files may take a bit longer depending on server load.

Will the audio from my AVI convert correctly?

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.

Does FLV support HD video?

Yes, FLV with H.264 encoding supports HD up to 1080p. The output resolution matches your source AVI.

Is this converter free?

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. No rate limits, up to 500MB files, simple REST endpoint.

View API Docs

Read our guides on file formats and conversion

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