Convert FLV to MP4 without uploading anything
Give old Flash videos a second life: Vidmini turns FLV files into standard MP4 videos that play on phones, TVs and in every modern app. Everything happens on your own device.
How it works
- 1
Choose or drop your FLV file. The first time, a 32 MB converter is downloaded from vidmini.com to read the format.
- 2
Keep MP4 as the output format. Vidmini reads the FLV on your device and prepares it for encoding.
- 3
Click FLV to MP4, then download the MP4 file. Your video was never uploaded.
What is an FLV file?
FLV (Flash Video) was the format of the Flash Player era. For years, most videos streamed on the web were delivered as FLV, and many people saved them to disk: clips downloaded from video sites, recorded webinars, e-learning modules, or recordings from older screen recorders and webcam apps that exported to Flash.
Flash Player reached its end of life in 2020, and browsers removed it. Today, most media players on phones, smart TVs and editing apps no longer open FLV files, and upload forms rarely accept them. Converting your archive to MP4 keeps those videos watchable.
How Vidmini reads FLV in the browser
Browsers can play MP4, WebM and a few other formats natively, but their video engine cannot read FLV. So Vidmini uses a fallback converter: FFmpeg compiled to WebAssembly, running inside the page on your own device. It unpacks the FLV first, then Vidmini encodes the result with your browser’s WebCodecs API, using the hardware encoder when one is available.
The first time you use it, the converter (about 32 MB) is downloaded from vidmini.com. Only the program is downloaded: your video is not sent anywhere. While it works, the page shows "Preparing this format for your browser", and a short note explains that the file was converted on your device first.
This extra step makes FLV conversions slower than, say, MOV to MP4. The fallback accepts FLV files up to 1 GB, which covers the vast majority of Flash-era videos.
What you get: an MP4 in H.264 and AAC
The output is an MP4 file with H.264 video and, when the FLV has sound, AAC audio. This is the most widely supported combination: it plays on Windows, macOS, iPhone, Android, smart TVs and in web browsers, and it is accepted by social networks and most upload forms.
The video is always re-encoded, so the conversion is never "lossless". Flash videos were usually small and heavily compressed to begin with; Vidmini keeps their original resolution, so the MP4 looks the same as the FLV at normal viewing size, but it cannot recover detail that the original encoding already removed.
Private by design
Your FLV file is processed entirely in your browser, with WebAssembly and WebCodecs. There is no upload, no account, no watermark and no tracking cookie. Our Content Security Policy only lets the page talk to vidmini.com to load its own code, including the converter.
Once the MP4 is ready, "Continue with this file" lets you pass it straight to another tool, for example to extract the soundtrack as an MP3, without choosing the file again.
Frequently asked questions
Can I play FLV files without converting them?
Some desktop media players still open FLV, but browsers, phones, TVs and most apps no longer do since Flash was retired. Converting to MP4 is the simplest way to make the video playable everywhere.
Why does the first conversion take longer?
Browsers cannot read FLV, so the first time you use this tool Vidmini downloads its 32 MB fallback converter from vidmini.com. The FLV is then unpacked on your device before being encoded to MP4. Your video is never uploaded.
Is the conversion lossless?
No. FLV files are always re-encoded to H.264, so the MP4 is a new encoding of the video. The original resolution is kept and the difference is usually hard to see, but it is not a bit-for-bit copy.
Is there a file size limit?
For formats that go through the fallback converter, like FLV, the input can be up to 1 GB. Most Flash-era videos are far smaller than that.
What if my FLV has no sound?
Then the MP4 simply has no audio track. When the FLV has sound, it is converted to AAC, the standard audio format for MP4.
Can I get just the audio from an FLV video?
Yes. After converting, use "Continue with this file" and pick the Video to MP3 tool to extract the soundtrack from the new MP4.
Which browsers work?
The latest Chrome, Edge, Safari and Firefox, on desktop and mobile. On a phone, very long videos are limited by free memory and storage, so a computer is more comfortable for big archives.