Convert MP4 to FLV

MP4 to FLV converter that runs entirely in your browser. 100% free, no signup, no upload — your files never leave your device. One-click batch conversion.

Conversions

Drop any file here or click to browse

All file types supported

About formats

MP4

MP4 (MPEG-4 Part 14) is a digital multimedia container format standardized by the Moving Picture Experts Group (MPEG). It stores video, audio, subtitles, and still images in a single file and is the most widely used format for streaming and sharing video across the web, mobile devices, and living-room hardware. MP4 offers an excellent balance between compression efficiency and quality, typically using the H.264 or H.265 (HEVC) video codec together with AAC audio. Its near-universal support makes it the default choice for social media platforms, browsers, phones, and modern TVs.

Developer: ISO/IEC (MPEG)
Initial release: 2001
Compression: Lossy
Color depth: up to 12-bit HDR
Transparency: No
Animation: Yes

Best for

Sharing videos on social media
Streaming video over the web
Playback on phones and tablets
Storing H.264 or HEVC video
Distributing downloadable video clips

Pros

+Near-universal support across devices and browsers
+Excellent compression-to-quality ratio
+Supports subtitles, chapters, and metadata
+Hardware-accelerated decoding on most devices

Cons

−Patent-encumbered H.264/HEVC codecs
−Not ideal for lossless archival
−Editing streams can require re-muxing

FLV

FLV (Flash Video) is a container format used to deliver video over the web using Adobe Flash Player. Although Flash has been discontinued, FLV files remain common in older video archives. FLV typically wraps Sorenson Spark or VP6 video and MP3 or AAC audio.

Developer: Adobe (Macromedia)
Initial release: 2002
Compression: Lossy
Color depth: 8-bit
Transparency: No
Animation: Yes

Best for

Recovering legacy Flash video archives
Migrating old web video content
Playing retro web animations
Archiving early-2000s online video
Converting old streaming clips

Pros

+Compact streaming for its era
+Wrapped common codecs like Sorenson Spark and VP6
+Widely used in historical web video
+Simple container structure

Cons

−Flash Player discontinued and unsupported
−Low maximum quality and 8-bit color
−No modern codec or HDR support
−Security risks in legacy Flash runtime

How to convert MP4 to FLV

1
Select MP4 files from your computer, Google Drive, Dropbox, a URL, or by dragging them onto the page.
2
Choose flv — or any other format you need as a result (more than 200 formats supported).
3
Let the file convert, then download your flv file right away.

MP4 vs FLV

Property	MP4	FLV
Compression	Lossy	Lossy
Color depth	up to 12-bit HDR	8-bit
Multi-track	Yes	Yes
DRM support	Yes	No
Open format	No	No

When to use MP4 vs FLV

MP4

Sharing videos on social media
Streaming video over the web
Playback on phones and tablets
Storing H.264 or HEVC video
Distributing downloadable video clips

FLV

Recovering legacy Flash video archives
Migrating old web video content
Playing retro web animations
Archiving early-2000s online video
Converting old streaming clips

Use cases for MP4 → FLV

Sharing videos on social media
Streaming video over the web
Playback on phones and tablets
Storing H.264 or HEVC video
Distributing downloadable video clips
Recovering legacy Flash video archives
Migrating old web video content
Playing retro web animations
Archiving early-2000s online video
Converting old streaming clips

Frequently Asked Questions

Is converting MP4 to FLV free?

Yes. This MP4 → FLV converter runs entirely in your browser and is completely free — no account, no credits, no watermark.

Which devices and platforms can I use to convert MP4 to FLV?

Any modern device with a current web browser: Windows, macOS, Linux, Android, iPhone and iPad. There is nothing to install — the conversion happens locally.

Are my MP4 files uploaded to a server?

No. Files never leave your device. The entire MP4 → FLV conversion runs locally in your browser, so your data stays private.

Can I convert multiple MP4 files at once?

Yes — batch conversion is supported. Add as many MP4 files as you like and convert them to FLV in one pass, then download the results together.

What is the maximum file size?

There is no fixed server-side limit because the conversion happens in your browser. Practical limits depend on the available memory and CPU of your device.

Will converting MP4 to FLV reduce the quality?

Because both formats use lossy compression, the FLV output will not bring back any quality that has already been lost in your MP4 file. Avoid repeated re-encoding to keep the best quality.

Does FLV support transparency?

No — FLV has no alpha channel. Transparent areas of your MP4 file will be filled with a solid background colour in the converted file.

How will the file size change after converting MP4 to FLV?

Both formats use comparable compression, so the FLV output will be similar in size to your MP4 file — typically within 10–20% of each other.

Related Conversions

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FREE

100% Free

No hidden fees, no subscriptions, and no limits. Enjoy complete access to all features gratis.

SIGNUP

No Signup Required

Start converting immediately without creating an account or sharing email address.

PRIVACY

Private & Secure

Your files never leave your device. All processing is completed locally for maximum privacy.

BATCH

Batch Conversion

Convert multiple files simultaneously to save time. Fast and efficient multi-file queue.

LOCAL

Runs in Browser

Utilizes advanced client-side WebAssembly technology to process files directly inside your tab.

FORMATS

200+ Formats

Supports a wide variety of formats including images, documents, audio, video, and more.

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