Convert MP4 to FLV Online Free

Convert MP4 to FLV (Flash Video) for compatibility with legacy systems, older web video players, or applications that still use Flash-based video playback.

Quick Answer

ChangeThisFile converts your MP4 video to Flash Video format using FFmpeg on our secure servers. Though FLV is a legacy format, some older streaming platforms and media workflows still require it. Files are auto-deleted after conversion, free to use with no signup needed.

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Convert MP4 to FLV

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Drag & drop your .mp4 file here, or click to browse

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MP4 vs FLV: Format Comparison

Key differences between the two formats

FeatureMP4FLV
TechnologyModern MPEG-4 standardAdobe Flash Video (legacy)
CodecH.264, H.265H.263 or H.264 (Sorenson Spark)
Browser supportUniversal native supportRequires Flash plugin (discontinued)
StreamingHLS, DASH streamingRTMP streaming (legacy)
File sizeEfficientLarger for equivalent quality
Use caseModern web and devicesLegacy Flash systems only
MetadataRich metadataBasic FLV metadata

When to Convert

Common scenarios where this conversion is useful

Legacy LMS and e-learning platforms

Older Learning Management Systems (LMS) built before 2015 may only support FLV video. Convert MP4 course content to FLV for compatibility with legacy e-learning software.

Archived website video restoration

Web archives and historical websites often used FLV for video. Convert existing MP4 content to FLV to recreate or archive original video experiences for historical purposes.

Legacy kiosk and POS systems

Some retail kiosk and point-of-sale systems with embedded browsers use legacy Flash video playback. FLV conversion ensures compatibility with these embedded systems.

Internal legacy corporate systems

Corporate intranets with embedded Flash video players may require FLV format. Convert MP4 training or presentation videos for playback on these internal systems.

How to Convert MP4 to FLV

  1. 1

    Upload your MP4 file

    Drag and drop your .mp4 file onto the converter, or click to browse. Files up to 500MB are supported.

  2. 2

    Server-side conversion

    Your file is securely uploaded and re-encoded using FFmpeg into FLV format. Processing typically takes a few seconds.

  3. 3

    Download the result

    Click Download to save your converted .flv file. The original and converted files are automatically deleted from our servers.

Frequently Asked Questions

No. Adobe Flash Player was discontinued in December 2020. Modern browsers no longer support FLV playback. Use FLV only for legacy systems that require it.

Some legacy enterprise systems, older LMS platforms, archived websites, and embedded hardware were built around Flash and have not been updated. FLV is needed to feed content into these systems.

FLV typically uses older, less efficient codecs than MP4. Re-encoding involves some quality trade-off. The output uses the best settings available for FLV.

Yes. Files are transferred over HTTPS and automatically deleted from our servers after conversion.

Yes. VLC Media Player supports FLV playback on all platforms.

The FLV output uses MP3 audio, which is compatible with most Flash-era players.

Files up to 500MB are supported.

Yes, completely free. No signup or subscription required.

Yes. Use the FLV to MP4 converter on ChangeThisFile to convert in the reverse direction.

Most conversions complete in a few seconds. Longer videos may take up to a minute.

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