video.webm

What is WebM?

WebM (VP8/VP9/AV1)

Open-source web video — royalty-free and browser-native

Container: WebM (subset of Matroska)
Video codec: VP8, VP9, AV1
Audio codec: Opus, Vorbis
File extension: .webm

Overview

WebM is an open, royalty-free video format developed by Google and released in 2010. It is based on the Matroska container and uses VP8, VP9, or AV1 for video and Opus or Vorbis for audio. Because it was designed for the web, all major browsers — Chrome, Firefox, Edge, and Safari — play WebM natively without plugins, making it the natural choice for HTML5 video.

WebM is widely used for browser-based recordings, screen captures, and animated content. Chrome's built-in screen recorder outputs WebM, as do tools like Loom, OBS (in web-export mode), and many WebRTC recording APIs. For distribution and editing outside the browser, WebM often needs to be converted to MP4 — but for web embedding, WebM is the superior choice due to its smaller file size and royalty-free status.

Technical Specifications

Container	WebM (subset of Matroska)
Video codec	VP8, VP9, AV1
Audio codec	Opus, Vorbis
File extension	.webm
MIME type	video/webm
Royalties	None — fully open source
Browser support	Chrome, Firefox, Edge, Safari (partial)

Advantages & Limitations

Advantages

✓ Completely royalty-free — no licensing fees
✓ Native browser support in Chrome, Firefox, and Edge
✓ VP9 achieves similar quality to H.264 at ~40% lower bitrate
✓ Supports alpha channel (transparent video) for overlays
✓ Used by YouTube internally for VP9/AV1 streaming
✓ Ideal for HTML5 <video> elements

Limitations

✕ Not supported by most desktop video editors without conversion
✕ Limited hardware decode support compared to H.264
✕ VP9 encoding is much slower than H.264 encoding
✕ Larger files than MP4 at equivalent quality for most encoders
✕ Not playable in Windows Media Player or QuickTime without codecs

Common Use Cases

HTML5 web video embedding
Browser-based screen recordings (Chrome recorder, Loom)
OBS exports for web delivery
WebRTC recordings
Animated web graphics (replacing GIF)
YouTube AV1 streaming delivery

Compatible Software & Platforms

WebM is natively supported by:

ChromeFirefoxEdgeOperaVLCMPVMPlayerYouTube (upload + streaming)HTML5 <video>

Convert WebM Files — Free Online Tools

Convert from WebM

WebM to MP4 → WebM to MKV → WebM to MOV → WebM to AVI → WebM to FLV → WebM to WMV →

Convert to WebM

MP4 to WebM → MKV to WebM → MOV to WebM → AVI to WebM → FLV to WebM → WMV to WebM →

Frequently Asked Questions

What is a WebM file?

A WebM file is a video file using the WebM (VP8/VP9/AV1) format. WebM is an open, royalty-free video format developed by Google and released in 2010.

What programs open WebM files?

WebM files are supported by: Chrome, Firefox, Edge, Opera, VLC, and most modern media players and editors.

What are WebM files used for?

Common uses include: HTML5 web video embedding; Browser-based screen recordings (Chrome recorder, Loom); OBS exports for web delivery.

WebM vs MP4: what is the difference?

WebM is royalty-free and browser-native; MP4 has broader device and editor support. WebM is typically chosen for html5 web video embedding, while MP4 is preferred for uploading to youtube, tiktok, instagram, and vimeo.

How do I convert a WebM file?

Convert WebM files online for free at MediaFormatter. Upload your file, choose a target format, and download the result — no installation or sign-up needed.