F4V
Flash MP4 Video
An MP4-based format Adobe created to replace FLV.
Commonly used for
Legacy web streaming video
F4V to OPUS Converter
Convert F4V files to OPUS free in your browser — no signup, no install, and the file is never uploaded to a server.
Completely free
Files are never uploaded
No signup required
Drop files or click to select
F4V → OPUS
What changes in this conversion
- OPUS is a newer format — check that the software or device you are sending it to supports it before switching.
- Only the audio track is kept — the video picture is discarded, so the result is far smaller than the original F4V file.
How to use
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Add your F4V file
Drag the F4V file onto the drop area above, or click it to pick a file from your device. You can add several files at once.
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Confirm OPUS as the output
OPUS is already selected as the output format on this page. You can pick the bitrate — higher keeps more of the sound, lower makes a smaller file.
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Run the conversion
Press the convert button. Video is re-encoded frame by frame on your own machine, so a long clip can take several minutes. The tab has to stay open.
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Download the OPUS file
When it finishes, download the OPUS file. Converting multiple files gives you the option to download them together as a ZIP.
About these formats
OPUS
Opus Audio
A modern codec offering the best efficiency available today for both speech and music. Discord, WhatsApp, and other real-time voice services use it.
Commonly used for
Voice calls, podcasts, low-bandwidth audio
Frequently asked questions
Is converting F4V to OPUS really free?
Yes. F4V to OPUS conversion is completely free with no signup, no watermark, and no daily limit on the free plan for ordinary use.
Are my F4V files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so the F4V file never leaves your device. That is also why it works without an internet connection once the page has loaded.
Will the OPUS file open everywhere?
OPUS is a newer format. Current browsers and phones handle it, but older desktop software may not — keep the original F4V if you have to send it to someone on an old machine.
Does the picture disappear when I convert F4V to OPUS?
Yes — OPUS is an audio format, so only the soundtrack is extracted. The video track is dropped, which is usually the point when you want just the audio.
Is there a file size limit for F4V to OPUS conversion?
The free plan handles files up to 200MB. Because processing happens on your own device, very large files depend on your computer's memory rather than a server quota.
Convert F4V files to other formats
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