MP4 to MKV
FreeConvert MP4 to MKV (H.264 + AAC).
Files up to 50MB process privately in your browser. Sign in to process larger files (up to 200MB) on our server instead.
Drag files here
Single file · MP4 / M4V · Max 200 MB
Files stay on your device — processing runs in your browser. Recent files are kept locally for 1 hour. Recent files are kept locally for 1 hour.
Showcase
See MP4 to MKV in action
Convert MP4 to MKV (H.264 + AAC).
- Private — files never leave your device
- Results update in the browser as you work
- Works on desktop and mobile browsers
How to use MP4 to MKV
A simple flow from start to result.
Add input
Upload a file or enter options in the workspace
Configure
Adjust settings for this tool
Process
Runs locally in your browser
Save
Preview the result, then download if you want
FAQs
Answers to the questions people ask most about privacy, quality, limits, and MP4 to MKV.
Yes. MP4 to MKV is free for everyday use. It runs in your browser with no account required for this tool.
For this tool, processing stays on your device in the browser. Files are not uploaded to Tools2Easy servers, so there is nothing for us to store or delete later. Close the tab when you are done if you want the in-memory preview cleared.
No install and no account for free tools. Open the page, add your file or text, process, then download or copy the result.
It depends on the settings. Lossy formats (like JPG/WebP) and compress tools trade some detail for a smaller file — use the quality controls when shown, and preview before you download. Lossless options (like PNG) keep full detail when available.
Accepted types for MP4 to MKV are listed in the upload area. Most browser tools work best under about 100 MB; very large files may fail or run slowly because your device does the work.
Yes, in modern mobile browsers (Chrome, Safari, Firefox, Edge). Large PDFs, images, or videos can be slower on phones because processing uses your device memory and CPU.
Browser tools depend on your device and file size — not a remote server queue. Close extra tabs, try a smaller file, or use a desktop browser if a large job stalls. If the tab crashes, the file was likely too heavy for available memory.
Yes. Results show in the workspace first. Download only when you are happy with the output. Use Compare on image/video results when you want to check against the original.
MP4 (H.264) is the most reliable in browsers. Other formats may work depending on your browser’s codecs. Check the upload hint for this tool.
Video decode and encode in the browser is heavy. Shorter clips and smaller resolutions finish faster. If the tab freezes, try trimming first or using a desktop browser with more RAM.
Not for this browser tool — frames are processed locally. Download the export when finished; nothing is stored on Tools2Easy servers.
JPG is smaller for photos, PNG keeps sharp edges and transparency, WebP is often smaller for the web, and PDF is best for documents or print packs. Use the dedicated converter when you already know the target format.