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Convert FLV to WebM

Ethical Tube's free FLV to WebM converter turns FLV videos into WebM, an open video format made for the web. It runs entirely in your browser, so your videos are never uploaded, and it's free with no sign-up or watermark. The first conversion downloads the FFmpeg engine (10 MB) once, and it's cached after that.

Files are converted on your device and never uploaded.

Price
Free
Uploads
None, it runs on your device
Sign-up
Not needed
Batch
Unlimited files
Output
WebM (VP9 + Opus)
First use
10 MB download, once

How it works

How to convert FLV to WebM

  1. Add your FLV files

    Drop FLV files onto the converter, click to choose them, or paste from the clipboard. Add as many as you like.

  2. Check the settings

    WebM is already selected. Keep the original resolution or pick a smaller one, and choose a quality.

  3. Download your WebM videos

    Each file gets its own download button as soon as it's ready. Download all saves everything in one ZIP file.

The formats

FLV and WebM at a glance

  • What is an FLV file?

    FLV is the Flash Video format that powered YouTube and most web video until the early 2010s. Adobe discontinued Flash in 2020 and browsers no longer play FLV, so old downloads and recordings in this format need converting to stay watchable. It opens in VLC, mpv, and some desktop media players. Browsers, phones, and QuickTime can't play it.

  • What is a WebM file?

    WebM is an open, royalty-free video format from Google, built for the web. It holds VP8, VP9, or AV1 video with Opus or Vorbis audio, and it's what Chrome and many screen recorders, including Ethical Tube, save by default. QuickTime, iMovie, and some editors can't open it. It opens in Chrome, Edge, Firefox, and Safari, VLC, YouTube, Google Drive, and editors like Shotcut and Kdenlive. QuickTime and iMovie can't open it.

Good to know

What changes when you convert FLV to WebM

  • If the video and audio already use codecs that WebM supports, they're copied without re-encoding, which is lossless and fast. Otherwise the video is converted to VP8 video with Opus audio.
  • Only the main video and audio tracks are kept. Subtitles, chapters, and extra audio tracks aren't carried over.
  • FLV files are converted with FFmpeg running in your browser. It's slower than a desktop app, so a long HD video can take several minutes.
  • The first conversion downloads FFmpeg compiled to WebAssembly (10 MB). It's cached, so later visits start quickly.
  • Copy-protected (DRM) files can't be converted.
  • Very long videos can run out of memory, especially on phones.

FAQ

Questions, answered

Is this FLV to WebM converter free?

Yes. It's completely free, with no sign-up, no watermark, and no limit on how many files you convert. It costs Ethical Tube nothing to run, because the conversion happens on your own device rather than on a server.

Are my files uploaded anywhere?

No. The conversion runs inside your browser with FFmpeg compiled to WebAssembly, so your files never leave your device. Once the page and the engine have loaded, it even works offline.

Does converting FLV to WebM lose quality?

Not if the codecs already fit: then the video and audio are copied as they are, with no loss. When they have to be re-encoded, the default quality keeps the result visually close to the original. Pick a higher quality for footage you plan to edit.

How long does it take?

When the video can be copied without re-encoding, a few seconds. Otherwise it depends on the video's length and resolution and on your device. With a hardware encoder, a 10-minute 1080p video usually takes a few minutes on a laptop.

Can I convert several FLV files at once?

Yes. Add as many as you like. They're converted one after another, and you can download each WebM file as soon as it's ready or all of them in one ZIP file.

Does it work on iPhone, Android, Mac, and Windows?

Yes, in any current browser on a computer or phone. FFmpeg runs on your processor without hardware acceleration, so long videos are much faster on a computer.

What can open a WebM file?

Chrome, Edge, Firefox, and Safari, VLC, YouTube, Google Drive, and editors like Shotcut and Kdenlive. QuickTime and iMovie can't open it.

Is there a file size limit?

There's no upload limit because nothing is uploaded. The practical limit is your device's memory: everyday files are fine, and a computer can usually handle videos up to about 2 GB.

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