FLV to MP4 Converter

Convert Flash Video FLV files to universally compatible MP4 online for free. Rescue old Flash-era videos. H.264 encoding. No software needed. Up to 100 MB.

256-bit SSL 500K+ conversions 4.9 rating Files auto-deleted in 2h

Tap to choose your FLV file

or

Also supports MP4, MOV, MKV, AVI, WebM, WMV • Max 100 MB

Your files are secure. All uploads encrypted via HTTPS. Files automatically deleted from our servers within 2 hours.

How to Convert FLV to MP4

1

Upload

Drag and drop your FLV video into the converter above, or click Choose FLV File to browse your device.

2

Convert

Click Convert to MP4. Our server re-encodes your Flash Video with H.264 + AAC for universal playback. Takes 30 seconds to 2 minutes.

3

Download

Click Download MP4 to save the converted video. That's it — no registration, no email required.

The Flash Video Problem: Why FLV Files No Longer Work

Flash Player is Dead

Adobe Flash Player reached end-of-life on December 31, 2020. Every major browser — Chrome, Firefox, Safari, Edge — has completely removed Flash support. The Flash Player plugin can no longer be installed, and Adobe itself included a kill switch that blocks Flash content from running. FLV files were designed to play inside Flash Player, so they became orphaned files overnight. Converting to MP4 is the only way to bring these videos back to life.

The Golden Era (2005–2015)

FLV was the web video format for a decade. YouTube launched in 2005 using FLV exclusively. Newgrounds, Metacafe, Google Video, Vimeo (early days), and countless other platforms all relied on Flash Video. If you downloaded web videos between 2005 and 2015 using tools like KeepVid, SaveFrom, or browser extensions, those files are almost certainly FLV. Converting them to MP4 preserves this content for the future.

Desktop Playback

VLC Media Player and PotPlayer can still open FLV files on desktop, but Windows Media Player, QuickTime, and the default media apps on Windows 10/11 and macOS cannot. Even with VLC, you cannot preview FLV files with Quick Look on Mac, thumbnails don't generate in file explorers, and no video editing software accepts FLV as input. Converting to MP4 makes your old Flash videos first-class citizens on every operating system.

Mobile & Smart TVs

No phone, tablet, or smart TV supports FLV playback. iOS has never supported Flash in any form. Android dropped Flash Player support in 2012 with Android 4.1. If you have FLV files from old downloads, archived websites, or backed-up hard drives, they are completely unplayable on any mobile device or television. MP4 with H.264 is the universal format that works on every screen.

What is FLV?

FLV (Flash Video) is a proprietary video container format developed by Macromedia (later acquired by Adobe in 2005). It was created specifically for delivering video content through the Adobe Flash Player plugin in web browsers.

FLV files typically contain video encoded with Sorenson Spark (a variant of H.263) or VP6, paired with MP3 or ADPCM audio. Later versions added support for H.264 video and AAC audio through the related F4V container. The format was optimized for low-bandwidth streaming in an era when most users had DSL or early broadband connections, so FLV files tend to be small with moderate quality.

At its peak, FLV powered virtually all web video. YouTube, Hulu, Dailymotion, Newgrounds, and millions of other websites used Flash Video as their primary delivery format. The format's decline began when Apple refused to support Flash on the iPhone in 2010, and ended definitively when Adobe discontinued Flash Player in December 2020. Today, FLV is a dead format — no browser, phone, or modern platform supports it natively.

What is MP4?

MP4 (MPEG-4 Part 14) is the international standard video container format, published as ISO/IEC 14496-14. It was derived from Apple's QuickTime MOV format in 2001, using the same atom/box architecture for organizing video, audio, and metadata.

MP4 supports H.264 and H.265 video with AAC audio, and includes the faststart flag (moov atom at the beginning) for instant web playback without buffering. It's the recommended upload format for YouTube, Instagram, TikTok, Facebook, and every major platform.

The defining strength of MP4 is universal compatibility. Every computer, phone, tablet, smart TV, gaming console, web browser, and media player manufactured in the last 15 years can play H.264 MP4 files. MP4 is effectively the successor to FLV as the standard web video format — but unlike FLV, it works natively without plugins, across every device and operating system.

FLV vs MP4: Quick Comparison

Feature FLV MP4
Developer Macromedia / Adobe (2003) ISO/MPEG (2001)
Status Dead (Flash EOL Dec 2020) Active standard
Video codecs Sorenson Spark, VP6, H.264 (F4V) H.264, H.265, AV1
Audio codecs MP3, ADPCM, AAC (F4V) AAC, MP3, AC-3
Typical quality 240p–480p (low-bandwidth era) Up to 4K/8K
File sizes Small (optimized for dial-up/DSL) Varies (efficient with H.264)
Browser support None (Flash removed from all browsers) All browsers (H.264)
Mobile support None (never supported on iOS) All phones and tablets
Smart TVs Not supported Universal
Desktop playback VLC only (no native support) Native on all OS
Streaming RTMP (deprecated) HLS, DASH (modern standards)
Best for Nothing (legacy format) Everything (universal standard)

Why Convert FLV to MP4?

Rescue your Flash-era archive

If you downloaded YouTube videos, Newgrounds animations, or web clips between 2005 and 2015, there's a good chance they're sitting on an old hard drive as FLV files. These videos — gaming moments, tutorials, music videos, Flash animations, early vlogs — represent a decade of internet culture that's increasingly hard to find online. Converting to MP4 ensures this content survives in a playable format.

Play on any device

FLV files are unplayable on iPhones, iPads, Android phones, smart TVs, gaming consoles, and all web browsers. Even on desktop, only VLC and a few third-party players can open them. Converting to MP4 with H.264 gives you a file that plays natively on every device manufactured in the last 15 years — no plugins, no special apps, no compatibility issues.

Edit and share old videos

No modern video editor — not iMovie, Premiere Pro, DaVinci Resolve, or CapCut — accepts FLV as input. If you want to edit, trim, combine, or add subtitles to old Flash videos, you must convert to MP4 first. The same applies to sharing: no social media platform, messaging app, or email service can handle FLV attachments.

Future-proof your collection

FLV is a dead format with zero ongoing development. The codecs inside (Sorenson Spark, VP6) are abandoned. As software evolves, even VLC may eventually drop FLV support. MP4 with H.264 is backed by the ISO standard and supported by every tech company on earth. Converting now means your videos will remain playable for decades to come.

Frequently Asked Questions

FLV files typically contain older codecs like Sorenson Spark (H.263) or VP6 at relatively low bitrates, so re-encoding to H.264 often produces equal or better visual quality at the same file size. Our converter uses CRF 23 which preserves all the detail present in the original FLV file. Since most FLV videos are 240p–480p from the pre-HD era, the quality ceiling is determined by the original, not the conversion process.
FLV (Flash Video) is Adobe's proprietary format designed for Flash Player, which was discontinued in December 2020. MP4 is the universal ISO standard supported by every modern device and browser. FLV files require third-party software like VLC to play and cannot be opened on phones, tablets, or smart TVs. MP4 plays everywhere natively without plugins or special apps.
Adobe Flash Player reached end-of-life on December 31, 2020, and every major browser — Chrome, Firefox, Safari, Edge — has completely removed Flash support. Adobe included a kill switch in the final Flash Player update that blocks all Flash content from running. FLV files were designed to play through Flash Player, so they no longer work in any browser. Converting to MP4 gives you a video that plays in all browsers natively using HTML5.
Yes, but only with third-party media players like VLC, PotPlayer, or MPC-HC. The default media apps on Windows (Movies & TV, Windows Media Player) and macOS (QuickTime) cannot play FLV files. Even with VLC, you won't get thumbnails in your file explorer, Quick Look previews on Mac, or the ability to use FLV files in video editors. Converting to MP4 makes your videos work with every application on your system.
FLV was the dominant web video format from roughly 2005 to 2015. If you used YouTube downloaders (KeepVid, SaveFrom, ClipConverter), saved Newgrounds animations, archived web videos, or used screen capture tools during that era, the output was almost always FLV. Browser cache extractors, Flash game downloads, and early video podcast tools also produced FLV files. These are digital artifacts from the Flash era that are worth preserving in a modern format.
We use FFmpeg with: H.264 video (libx264, CRF 23, medium preset) for excellent quality at reasonable file sizes, AAC audio at 192 kbps for transparent audio quality, YUV420p pixel format for universal device compatibility, and faststart for instant web playback. These settings are optimized for the best balance of quality, compatibility, and file size.
Yes. Convertio.com offers free FLV to MP4 conversion with no watermarks, no registration, and no email required. Upload your file, convert, and download. Your files are encrypted during transfer and automatically deleted from our servers within 2 hours.

Related Video Conversions