YouTube uses it for streaming, all modern browsers play it natively in HTML5 ( ), and it's the format of choice for web videos without needing a plugin or H.264 license.

Compress a WEBM video

Compress WebM files, the open-source video format pushed by Google (VP9/AV1 codecs + Opus/Vorbis audio).

Accepted source formats

WEBM

How it works

Drop your WebM.

Adjust quality (CRF 30 = good quality, 40 = light file).

Download the compressed WebM, ready to embed in an HTML5 <video> tag.

Common mistakes

Using a source file of poor quality.
Publishing without checking the final result.
Confusing file size, dimensions and quality.
Overwriting the original file without keeping a copy.

Pro tips

Always keep an original version.
Test several settings before downloading.
Use WebP for the web when possible.
Choose descriptive file names for SEO.

Privacy and file handling

File handling depends on the selected tool and format. For sensitive files, review the tool information before starting the operation.

How to convert a WEBM file to Compress a WEBM video?

Drag and drop or select your WEBM file from your device. Click "Convert" and wait a few seconds. Get your converted Compress a WEBM video file instantly. Always check the output file before sharing it. If a file fails, try a smaller version or split it when the tool supports that workflow.

Supported formats

Source format: WEBM. Target format: Compress a WEBM video. The final format should match how you plan to use it. Choose a file, run the conversion, then check the result before downloading it. The practical file-size limit depends on the format, browser and memory available on your device.

What is the maximum WEBM file size?

The practical file-size limit depends on the format, browser and memory available on your device. If a file fails, try a smaller version or split it when the tool supports that workflow. Some elements may change during conversion, so open the output and check it before using or sharing it.

Which browsers are compatible?

Use a recent, up-to-date browser. Behaviour can vary with the file format, available memory and the features supported by your device. Always check the output file before sharing it. The final format should match how you plan to use it. Keep the original until you have approved the result.

Can I use the tool on mobile?

You can try the tool on a phone or tablet with a recent browser. Large files may require more memory or be easier to process on a desktop computer. Choose a file, run the conversion, then check the result before downloading it. Current quotas and higher plans are shown on the Pricing page.

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Guides and tutorials

Learn how to use our tools with our detailed guides.

Blog — Convert Video

Frequently asked questions

YouTube uses it for streaming, all modern browsers play it natively in HTML5 (<video>), and it's the format of choice for web videos without needing a plugin or H.264 license.

WebM offers better compression (VP9/AV1) and is royalty-free, but MP4 (H.264) is still more universally supported (iOS Safari 13+ for WebM, all iOS for MP4). Choose based on audience.

Yes, WebM with VP9 supports alpha — useful for embedding a video on a website with transparent background (e.g. an animated mascot).

Yes, our conversion tool offers WebM → MP4 in one click. Opus audio is converted to AAC for iPhone/iPad compatibility.

AV1 is slower than H.264 (~5x), but our tool uses fast presets that remain usable in practice. For real time savings, prefer VP9 which is still very efficient.