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F4V to WEBM converter

Convert F4V to WEBM in your browser. No upload and no account: the file never leaves your device, so the only size limit is your device’s memory.

I want WEBM
Quality

Applies only when the video has to be re-encoded. A straight copy keeps the original quality.

Advanced 2
Always re-encode Rebuilds the picture as H.264 (VP9 for WebM) even when it could be copied. Fixes files that won’t play on older TVs and PCs.

Bytes of your files sent anywhere: 0 B

Related conversions

Other ways to convert F4V

Convert other formats to WEBM

Read more about the F4V format and the WEBM format, or see every video tool and all video conversions.

Should you convert F4V to WEBM?

Yes, when a device or app needs WEBM. WEBM can’t carry the H.264 video found in F4V files, so the picture is re-encoded as VP8, VP9 or AV1, which takes about as long as the clip on a recent laptop.

WEBM also plays in far more places: Chrome, Firefox, Edge and recent Safari, but not the iPhone Photos app, many editors or social uploads.

F4V is an MP4-style file from late-era Flash video; WEBM is the web’s open video format, holding VP8, VP9 or AV1 video with Opus or Vorbis audio. Use WEBM for video on your own website, especially short loops and clips with transparency.

F4V and WEBM compared
Property F4V WEBM
Usually contains H.264 video with AAC audio VP9 or AV1 video with Opus audio
Support A legacy format Opens in current browsers and apps
Plays on VLC and some editors; browsers don’t recognize the extension Chrome, Firefox, Edge and recent Safari, but not the iPhone Photos app, many editors or social uploads
Best for Nothing today; convert old Flash-era video Video embedded in web pages, and browser screen recordings
Introduced 2007 2010

How to convert F4V to WEBM

  1. 01

    Add your F4V

    Drop your F4V video onto the box, or click to choose it. It is read from your disk and stays there.

  2. 02

    Check the settings

    The output is already set to WEBM. Change the quality if you want to; the defaults suit most files.

  3. 03

    Save the WEBM

    Press convert and save the WEBM. Several files come back together as a ZIP.

What changes when F4V becomes WEBM

Re-encoded, at a quality you choose

Because the video has to be compressed again, a little detail is lost. The default quality keeps the difference invisible; choose High for footage you’ll edit further.

WebM needs the web’s codecs

WebM holds only VP8, VP9 or AV1 video with Opus or Vorbis audio, so most F4V files are re-encoded to VP9 and Opus. Recent Chrome and Edge do this on your graphics hardware; other browsers use a slower software encoder.

The size stays about the same

F4V and WEBM are close in size for the same content, so do this for compatibility rather than to save space. F4V: The same as the equivalent MP4. WEBM: Usually a little smaller than MP4 at the same quality.

A one-time engine download

F4V is read by FFmpeg compiled to WebAssembly, a 31 MB download the first time. It is slower than your browser’s built-in video decoder, but nothing is uploaded and the engine stays cached for next time.

This page is put together from our notes on each format, choosing only what is true of F4V and WEBM, so every pairing states the same facts the same way. How these pages are made.

Why it doesn’t upload

Video files are big, and uploading one just to change its container can take longer than the conversion itself. Your browser can read and write these formats, so the file never has to leave your device.

How to check for yourself

Worth knowing

  • About the F4V. Because F4V already holds H.264 and AAC, it usually moves into MP4 without re-encoding at all.
  • About the WEBM. Browser screen recorders save WEBM, and the recording then fails to upload or attach almost everywhere else.
  • MP4, MOV, MKV and WebM are handled by your browser’s own video engine, often with hardware help. AVI, WMV, FLV, MPG and the other older formats use the FFmpeg engine, a one-time 31 MB download, and are slower.

Questions

Does converting F4V to WEBM lose quality?

The video is re-encoded, so a little detail is lost, but the default quality is set high enough that it doesn’t show.

Will a WEBM play on my phone?

WEBM opens in current browsers and apps: Chrome, Firefox, Edge and recent Safari, but not the iPhone Photos app, many editors or social uploads. Drag it into Chrome, Firefox or Edge, or open it in VLC.

Read more about this

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