Bulk Convert MKV to WEBM
Drag & drop your MKV file here, or click to choose
MKV files only
You can drop or select several files at once.
Your file is never uploaded — everything runs in your browser.
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Related tools
MKV (a flexible container that holds almost anything) and WebM (a light, royalty-free web video format). This free tool converts MKV to WEBM directly in your browser, so your file never leaves your device. No install and no sign-up needed.
Batch conversion, ZIP download and quality control
- Convert many files at once — drop or pick several MKV files and they are converted one after another.
- When you convert two or more files, the results are bundled into a single ZIP so you download everything in one click.
- Adjust quality and size: lower the quality or resize to make the WebM files smaller. The setting applies to every file in the batch.
How to convert MKV to WEBM
- 1Drop your MKV file onto the box above, or click to choose it.
- 2Adjust the options if you like (resolution, bitrate or frame rate — for GIF, the fps and width).
- 3Click "Convert to WebM" and wait a moment.
- 4Download the WebM file — it is saved straight to your device.
Common uses
- Make a MKV clip play everywhere by converting it to WEBM.
- Meet a social upload requirement, extract the audio or make a short GIF.
- Reduce file size while keeping a WEBM version that plays smoothly.
Quality & compatibility notes
- Both MKV and WebM are lossy formats, so re-encoding may slightly reduce quality.
- Re-encoding video can take a while and runs entirely in your browser.
- Everything runs in your browser — your file is never uploaded.
Frequently asked questions
Is my MKV file uploaded when I convert it to WebM?＋
No. The conversion runs entirely in your browser using your device, so your file is never sent to any server.
Will the quality drop when I convert MKV to WEBM?＋
Both MKV and WebM are lossy formats, so re-encoding may slightly reduce quality.
Can I convert several MKV files to WebM at once?＋
Yes. Add multiple files and they are converted one by one in your browser. A single file downloads directly; two or more are packed into one ZIP. If one file fails, the others still convert.
Is it free? Do I need to sign up?＋
Yes, it is completely free — no sign-up, no install and no watermark.
Is there a file size limit?＋
You can convert files up to 200 MB. Everything is processed on your device, so very large files depend on your available memory.
Can I convert the other way, from WebM back to MKV?＋
That direction is not available right now. MKV can still be converted to several other formats.
Private by design
Everything runs in your browser — your file is never uploaded.