Convert MP4 to FLV
Convert MP4 files to FLV locally, completely free and with maximum privacy.
Drag and drop your files here
or click to browse local files (large files supported, limited only by browser RAM)
Upload FilesPlatform Statistics
How to convert MP4 to FLV
- Drop your .mp4 files above, or click Upload Files. You can add many files at once.
- FLV is already selected as the output. Open the settings (gear icon) to fine-tune the result.
- Click Convert All. FFmpeg runs inside your browser through WebAssembly; nothing is uploaded.
- Download your .flv files as soon as each one finishes.
What to know about MP4 to FLV conversion
- The video is re-encoded to H.264 video and AAC audio so it plays wherever FLV is supported, and odd frame sizes are adjusted automatically.
- You can change the resolution, frame rate, playback speed and quality (CRF) before converting.
MP4 vs FLV
| Feature | MP4 (MPEG-4 Part 14) | FLV (Flash Video) |
|---|---|---|
| Codecs used by PureConverter | H.264 video and AAC audio | H.264 video and AAC audio |
| Best for | sharing and streaming video on any device | legacy Flash-based players and old streaming setups |
| Opens in | every browser, phone, TV and media player | VLC, mpv and most media players |
MP4 (MPEG-4 Part 14): A widely compatible digital multimedia container format, most commonly used to store video and audio.
FLV (Flash Video): A legacy streaming video container popularised by Adobe Flash Player.
Conversion options
- Resolution: original, 1080p, 720p, 480p or 360p
- Frame rate and playback speed (0.5× to 2×)
- Quality presets or a custom CRF value, and lossless mode
- Audio bitrate, sample rate and channels
Frequently asked questions
Is it safe to convert MP4 to FLV here?
Yes. Your files are processed entirely on your own device by WebAssembly code running in the browser. They are never uploaded, so nobody else can see them, and the converter keeps working even if your connection drops after the page loads.
Is there a file size limit?
There is no server-side limit. The only limit is the memory available to your browser, typically 1.5–4 GB on desktop computers.
Can I convert several MP4 files at once?
Yes. Add as many files as you like; they are converted in parallel according to your device's CPU cores, and you can apply the same settings to all of them.
Related conversions
Need the opposite? Convert FLV to MP4.
Convert MP4 to other formats
- MP4 to MP3
- MP4 to WEBP
- MP4 to GIF
- MP4 to WAV
- MP4 to MOV
- MP4 to M4A
- MP4 to FLAC
- MP4 to WEBM
- MP4 to MKV
- MP4 to AAC
- MP4 to OGG
- MP4 to OPUS
Convert other formats to FLV
- MOV to FLV
- WEBM to FLV
- MKV to FLV
- AVI to FLV
- WMV to FLV
- M4V to FLV
- MPEG to FLV
- TS to FLV
- 3GP to FLV
- OGV to FLV
See every MP4 converter and FLV converter, or browse the full converter directory.