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Free MP4 to WebM
Converter Online

Convert MP4 to WebM online free. Create smaller, web-optimized WebM videos for HTML5 embedding, web development, and Google's open video format — no upload, 100% private.

100% PrivateLightning FastForever Free

Upload Your Video

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or drag & drop video files here

Supports MP4, WebM, MOV, AVI

MP4 to WebM Conversion Settings
Convert your MP4 video to WebM format in your browser.
2.5M+

Video Conversions

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100% Private MP4 to WebM Conversion

Convert MP4 to WebM entirely in your browser using FFmpeg.wasm. Your video files are never uploaded to any server — complete privacy for personal videos, client content, and sensitive recordings.

Smaller File Size for Web

WebM with VP9 encoding delivers significantly smaller file sizes than MP4 at equivalent visual quality. Convert your MP4 videos to WebM to reduce bandwidth costs and improve page load times.

Perfect for HTML5 Video & Web Embedding

WebM is natively supported in all modern browsers (Chrome, Firefox, Edge, Opera) and is the preferred format for the HTML5 <video> tag. Convert MP4 to WebM for seamless web integration.

VP9 Encoding for Maximum Efficiency

Our MP4 to WebM converter re-encodes your H.264 MP4 to VP9 WebM — Google's open video codec that offers 30–50% better compression than H.264 at the same visual quality.

How to Convert MP4 to WebM Online Free

Convert your MP4 video to WebM in 3 simple steps

01

Upload Your MP4 File

Select your MP4 file from your computer, phone, or tablet. Our free online MP4 to WebM converter handles any MP4 — downloaded videos, screen recordings, exports, and more.

02

Select WebM as Output

WebM is automatically selected as the output format. The converter will encode your MP4 to VP9 WebM, optimized for web playback and smaller file size.

03

Convert MP4 to WebM & Download

Click convert and download your WebM file instantly. The entire MP4 to WebM conversion runs in your browser — completely free, no upload, 100% private.

Best Free MP4 to WebM Converter Online

Unlike other online converters that upload your MP4 files to remote servers, our MP4 to WebM converter processes everything locally in your browser with FFmpeg.wasm. Get complete privacy, no file size limits, and no registration required.

Web-optimized Output

VP9 WebM files are smaller and stream faster than MP4 in browsers.

No Upload Required

MP4 files stay on your device — zero server exposure.

FeatureOur ToolOthers
100% Browser-based (No Upload)
Fast MP4 to WebM Conversion
Unlimited MP4 File Size
Forever Free MP4 to WebM Converter
No Software Installation Required
High-quality VP9 WebM Output
WebM, MP4, MOV Output Supported

MP4 to Video Format Support

Convert MP4 and other video formats to WebM, MOV, and more

Input Video Formats

MP4Convert MP4 to WebM — universal video format
MKVConvert MKV to WebM — Matroska container format
MOVConvert MOV to WebM — Apple QuickTime format
AVIConvert AVI to WebM — classic Windows video format
FLVConvert FLV to WebM — Flash video format
WebMConvert WebM to MP4 — Google web video format

Output Video Formats

WebMWebM — open format optimized for web embedding
MP4MP4 — universal format for all devices and platforms
MOVMOV — Apple QuickTime format for Mac and iPhone

MP4 to WebM Converter Reviews

Trusted by web developers, content creators, and engineers worldwide

Jordan F.

Frontend Developer

Developer
"I use WebM for HTML5 background videos to keep page load times fast. This converter turns my MP4 clips into smaller WebM files instantly, right in my browser. Perfect tool."
Mia C.

Web Designer

Designer
"My client's landing page needed a WebM video for the hero section. Converting the MP4 in the browser was instant — no upload, no privacy concerns. The file size was 40% smaller."
Sam R.

Video Production Manager

Production
"We deliver content in both MP4 and WebM for maximum browser compatibility. This browser-based converter makes generating WebM versions of our MP4 master files effortless."
Jordan F.

Frontend Developer

Developer
"I use WebM for HTML5 background videos to keep page load times fast. This converter turns my MP4 clips into smaller WebM files instantly, right in my browser. Perfect tool."
Mia C.

Web Designer

Designer
"My client's landing page needed a WebM video for the hero section. Converting the MP4 in the browser was instant — no upload, no privacy concerns. The file size was 40% smaller."
Sam R.

Video Production Manager

Production
"We deliver content in both MP4 and WebM for maximum browser compatibility. This browser-based converter makes generating WebM versions of our MP4 master files effortless."
Jordan F.

Frontend Developer

Developer
"I use WebM for HTML5 background videos to keep page load times fast. This converter turns my MP4 clips into smaller WebM files instantly, right in my browser. Perfect tool."
Mia C.

Web Designer

Designer
"My client's landing page needed a WebM video for the hero section. Converting the MP4 in the browser was instant — no upload, no privacy concerns. The file size was 40% smaller."
Sam R.

Video Production Manager

Production
"We deliver content in both MP4 and WebM for maximum browser compatibility. This browser-based converter makes generating WebM versions of our MP4 master files effortless."
Jordan F.

Frontend Developer

Developer
"I use WebM for HTML5 background videos to keep page load times fast. This converter turns my MP4 clips into smaller WebM files instantly, right in my browser. Perfect tool."
Mia C.

Web Designer

Designer
"My client's landing page needed a WebM video for the hero section. Converting the MP4 in the browser was instant — no upload, no privacy concerns. The file size was 40% smaller."
Sam R.

Video Production Manager

Production
"We deliver content in both MP4 and WebM for maximum browser compatibility. This browser-based converter makes generating WebM versions of our MP4 master files effortless."
Lily Z.

Indie Game Developer

Game Dev
"WebM is the standard for web game cutscenes. Converting my MP4 trailers to WebM for my web-based game is now a one-click process. Smaller files, better performance."
Owen M.

Digital Marketer

Marketing
"Our landing page videos were slowing down the site. Converting from MP4 to WebM cut the video file sizes in half. This tool made it easy — no server upload, completely private."
Tara H.

Developer

Tech
"FFmpeg.wasm in the browser for MP4 to WebM conversion is exactly what privacy-conscious developers need. No server, no upload, zero data exposure. Highly recommended."
Lily Z.

Indie Game Developer

Game Dev
"WebM is the standard for web game cutscenes. Converting my MP4 trailers to WebM for my web-based game is now a one-click process. Smaller files, better performance."
Owen M.

Digital Marketer

Marketing
"Our landing page videos were slowing down the site. Converting from MP4 to WebM cut the video file sizes in half. This tool made it easy — no server upload, completely private."
Tara H.

Developer

Tech
"FFmpeg.wasm in the browser for MP4 to WebM conversion is exactly what privacy-conscious developers need. No server, no upload, zero data exposure. Highly recommended."
Lily Z.

Indie Game Developer

Game Dev
"WebM is the standard for web game cutscenes. Converting my MP4 trailers to WebM for my web-based game is now a one-click process. Smaller files, better performance."
Owen M.

Digital Marketer

Marketing
"Our landing page videos were slowing down the site. Converting from MP4 to WebM cut the video file sizes in half. This tool made it easy — no server upload, completely private."
Tara H.

Developer

Tech
"FFmpeg.wasm in the browser for MP4 to WebM conversion is exactly what privacy-conscious developers need. No server, no upload, zero data exposure. Highly recommended."
Lily Z.

Indie Game Developer

Game Dev
"WebM is the standard for web game cutscenes. Converting my MP4 trailers to WebM for my web-based game is now a one-click process. Smaller files, better performance."
Owen M.

Digital Marketer

Marketing
"Our landing page videos were slowing down the site. Converting from MP4 to WebM cut the video file sizes in half. This tool made it easy — no server upload, completely private."
Tara H.

Developer

Tech
"FFmpeg.wasm in the browser for MP4 to WebM conversion is exactly what privacy-conscious developers need. No server, no upload, zero data exposure. Highly recommended."

Free MP4 to WebM Converter Online — Convert Video for Web

Need to convert MP4 to WebM online free? Our browser-based MP4 to WebM converter encodes your videos to Google's open format instantly — no upload required. Whether you're a web developer embedding HTML5 video or a creator optimizing for web, convert MP4 to WebM for smaller file sizes and native browser support.

WebM is Google's open-source video format, designed specifically for the web. Unlike MP4, WebM is royalty-free and offers significantly better compression with VP9 or AV1 encoding — typically 30–50% smaller file sizes at the same visual quality. Web developers prefer WebM for HTML5 <video> tags to reduce bandwidth costs and improve page load times. WebM is natively supported in Chrome, Firefox, Edge, and Opera. Our free MP4 to WebM converter makes this conversion instant, private, and unlimited.

Why convert MP4 to WebMWhy convert MP4 to WebM

MP4 to WebM Converter FAQ

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