WMA to MKV
Convert WMA audio to MKV โ right in your browser, nothing uploaded.
Drag & drop your WMA files here, or click to choose. Everything runs in your browser — nothing is uploaded.
WMA is Microsoft's Windows Media Audio format, and outside Windows it is close to a dead end: most iPhones, Android music apps and car stereos will not open it. MKV (Matroska) is an open container, and an audio-only MKV holds that audio track inside a Matroska file, which is what you want when your media server, editing setup or toolchain already expects Matroska. This converter does the whole job inside your browser using a WebAssembly build of FFmpeg, so your files are never uploaded anywhere. It is completely free, needs no signup or install, accepts several files at once, and lets you pick a bitrate from 96 to 320 kbps, with 192 as the default. Every finished file gets an inline preview player and a Download button.
Frequently Asked Questions
How do I convert WMA to MKV?
To convert WMA to MKV, first pick your quality from the Bitrate dropdown above the drop area โ 96k, 128k, 192k (the recommended default), 256k, or 320k โ then drag your WMA files onto the drop area or click it to browse. Conversion to MKV starts automatically as soon as the files are added. You can add several WMA files at once and they are processed one after another, so set the bitrate before you drop them in. Each finished file appears as its own row showing the new filename and size, an inline player to preview the audio, and a Download button. Everything runs in your browser through a WebAssembly build of FFmpeg, so nothing is uploaded to a server.
Why would I convert WMA to MKV instead of MP3?
Convert to MKV when something further down your workflow expects a Matroska file, since an audio-only MKV simply carries the audio track inside the open Matroska container. If your goal is just getting the audio to play on a phone, in a car stereo or in a music app, MP3 or M4A is the safer pick. MKV is a container decision rather than a compatibility upgrade, so choose it when Matroska is what the next tool in your chain asks for.
Is this WMA to MKV converter really free and private?
Yes. It is completely free with no signup, no account, no watermark and no software to install, and it is private in a literal sense: the conversion runs inside your own browser with a WebAssembly build of FFmpeg, so your WMA files are never uploaded to any server. That makes it safe for confidential audio such as interviews, dictation, lecture recordings or client calls, because the sound never leaves your device.
Will converting WMA to MKV reduce the audio quality?
Slightly, yes. WMA is a lossy format and the MKV output here is lossy too, so the audio is decoded and re-encoded, which means a second lossy pass. Nothing can recover the detail the original WMA encode already discarded, but a higher bitrate keeps the difference very hard to hear. Choose 256 or 320 kbps if you want the re-encode to stay as close to the source as possible; 192 kbps is the default and is fine for casual listening and speech.
Which bitrate should I choose for my MKV file?
Pick 192 kbps if you are unsure - it is the default and a sensible balance of quality against file size. Go to 256 or 320 kbps when the source WMA was encoded at a high bitrate and you want to preserve as much of it as possible, and drop to 96 or 128 kbps for spoken word where small files matter more. Encoding above the source WMA's own bitrate cannot add quality back; it only makes the MKV larger.
Is there a file size limit, and can I convert several WMA files at once?
There is no size limit imposed by this site, because nothing is uploaded - the only real limit is your own device's memory. You can also drop in multiple WMA files at once and they will be converted one after another, each finished file getting its own preview player and Download button. Very large files, roughly over a few hundred megabytes, can be slow or run out of memory on a phone, so use a desktop browser for long recordings.
Does it work on iPhone, Android and Mac?
Yes. The converter runs in any modern browser on Windows, Mac, Linux, iPhone and Android, with no app to install and no queue to wait in. Because the work happens on your own device, the only requirement is a browser that supports WebAssembly, which every current version of Chrome, Safari, Firefox and Edge does. On a phone, keep the tab open while it works, and switch to a desktop browser if the recording is long.