FLV to MP4
FLV was the video format that powered YouTube and Flash video for over a decade — but Flash is dead and FLV files are unplayable on modern devices without special software. Converting to MP4 brings your old Flash videos into the modern era with universal playback. FluidConvert handles FLV to MP4 free in your browser.
Drop your file here, or browse
Accepts: video/x-flv, .flv · Max 100MB (free)
Your files are encrypted with TLS and automatically deleted after conversion.
Simply upload your .FLV file and we'll convert it to .MP4 format — fast, free, and secure.
Fast & Free
Convert files up to 100MB at no cost. No account needed.
Secure
Files are encrypted and automatically deleted after conversion.
High Quality
Industry-leading conversion with no quality loss.
How to Convert FLV to MP4
Upload Your File
Click the upload area above or drag and drop your .FLV file. We support files up to 100MB on the free plan.
Choose Output Format
Select .MP4 as your target format. Adjust any conversion settings if needed.
Download Your File
Click Convert Now and wait a few seconds. Once complete, download your converted file instantly.
About FLV to MP4
What is FLV?
FLV (Flash Video) was developed by Macromedia (later Adobe) and became the dominant web video format from the mid-2000s through the early 2010s. YouTube, Vimeo, Hulu, and virtually every major video platform served content as FLV during this era, requiring Adobe Flash Player to play. FLV typically uses the H.263 or older MPEG-4 Part 2 video codec with MP3 or AAC audio. Adobe officially ended Flash Player support in December 2020, leaving FLV files stranded on legacy computers and hard drives.
Why convert to MP4?
MP4 is the universal video standard that plays natively on every modern device — phones, tablets, smart TVs, streaming sticks, game consoles, and every major operating system. Converting your FLV archive to MP4 preserves your video content in a format that will remain playable and compatible for the foreseeable future. MP4 also supports higher quality codecs (H.264, H.265) than FLV's older compression.
What to expect from the conversion
FLV video is re-encoded to H.264 inside an MP4 container. Since FLV files from the Flash era were often encoded at low resolutions (360p or 480p) and low bitrates, the MP4 output will reflect the original quality — converting can't recover resolution or detail that wasn't in the source. File sizes are comparable or slightly smaller. Audio transfers cleanly from MP3 or AAC in the FLV to AAC in the MP4.
How FluidConvert handles it
We decode the FLV container fully, handling both H.263 and MPEG-4 Part 2 video streams, and re-encode to H.264/AAC inside an MP4 container optimized for device compatibility. The entire process runs on our servers — no Flash or legacy software needed.
Common reasons to convert FLV to MP4
- Preserving a personal archive of downloaded YouTube videos from the Flash era that are no longer available online
- Converting old FLV recordings from Camtasia, Captivate, or other Flash-era screencasting tools
- Making a collection of downloaded web video tutorials playable on a modern phone or tablet
- Archiving FLV files found on old hard drives or backup media before the storage degrades
Frequently Asked Questions
Can I recover better video quality from an old low-resolution FLV?
No. If your FLV was encoded at 360p or 480p, that's all the detail stored in the file. Converting to MP4 preserves that quality but can't add pixels or sharpness that weren't there. The benefit of conversion is compatibility, not quality improvement.
Will my FLV video from YouTube's early days convert correctly?
Yes. Early YouTube FLV files used H.263 or Sorenson Spark video with MP3 audio — these are fully supported. Some FLV files use the VP6 codec (used by Flash for higher quality), which is also supported by FluidConvert.
Are FLV and SWF files the same thing?
No. FLV is a video container format containing video and audio streams. SWF is an Adobe Flash application format that can contain interactive elements, animations, and embedded FLV video. FluidConvert converts FLV files — SWF files are Flash applications and would need different handling.