Is this MKV to AAC converter really free?

Yes. Up to 5 files at a time, no signup, no catch. The free tier adds a small watermark to image output — Pro ($9.99/mo or $49/yr) removes it, raises the file size limit to 500 MB, and unlocks unlimited batch conversion.

Are my files uploaded to a server?

No — and you can verify it yourself. Open DevTools → Network tab, then convert a file. You'll see zero upload requests. Everything runs right in your browser. We never see your files.

How long does conversion take?

Usually 1–3 seconds for a typical file. The very first conversion on a fresh page load may take 5–20 seconds while the converter engine loads — after that it's instant. Your CPU does all the work locally.

What is the file size limit?

Free: up to 10 MB per file, 5 files per batch. Pro: up to 500 MB per file, unlimited batch. If you're working with large videos or RAW photos, Pro is built for that.

Can I batch convert multiple MKV files at once?

Yes — drop multiple files at once (or Ctrl/Cmd+click to select them) and they all convert in parallel. Free accounts handle up to 5 files per batch; Pro has no limit.

What bitrate will the converted audio use?

We default to 192 kbps for MP3, 128 kbps for OGG/Opus, and 320 kbps for M4A/AAC. These settings are perceptually transparent — most listeners can't tell the difference in a blind test.

Will my metadata (ID3 tags, album art) be preserved?

Yes, when both formats support it. Tags carry over on conversions like MP3→M4A or FLAC→MP3. WAV has limited tag support, so some metadata may not transfer.

If the MKV already contains AAC audio, is extraction lossless?

Yes — if the source MKV track is AAC, the converter extracts it directly without re-encoding, preserving exact quality.

What if the MKV contains DTS or AC3 audio instead of AAC?

The converter will re-encode from DTS or AC3 to AAC. Quality is maintained at high bitrate, though re-encoding from one lossy codec to another introduces a small quality reduction.

How private is this converter?

Completely private — by design, not policy. There is no upload endpoint. Files are processed right inside your browser tab and disappear the moment you close it. We collect only anonymous page-view counts; your file content is never seen or stored.

MKV to AAC Converter — Free, Online, No Upload

How to convert MKV to AAC online

1
Drop your MKV file
Drag and drop your Matroska Video file onto the converter, or click to browse your files. You can select up to 5 at once. Nothing leaves your device — conversion happens right here in the browser.
2
Hit Convert — it happens locally
Click Convert and watch it go. There's no upload, no server queue, no waiting. The converter runs Matroska Video → Advanced Audio Coding entirely in your browser tab. Most files finish in 1–3 seconds.
3
Download your AAC
Your Advanced Audio Coding file is ready. Click Download, or grab a ZIP if you converted a batch. Close the tab and everything disappears — no copies kept anywhere.

MKV vs AAC: format overview

MKV

Matroska Video

Matroska.org · 2002

Compression: lossy
Transparency: No

✓ Supports virtually any codec combination
✓ Multiple audio tracks and subtitles per file
✗ Not natively supported by iOS or older devices

AAC

Advanced Audio Coding

Dolby, Fraunhofer, Sony, Nokia · 1997

Compression: lossy
Transparency: No

✓ Successor to MP3 — better quality at same bitrate
✓ Native support across Apple, Android, YouTube

MKV magic bytes: 1A 45 DF A3

AAC magic bytes: FF F1 (ADTS) / 00 00 00 xx 66 74 79 70

Why convert MKV to AAC?

MKV is a fantastic archive format for video, but its audio tracks are invisible to the platforms that matter most for modern audio distribution. Streaming services, mobile apps, and Apple devices all rely on AAC as their native codec, and an MKV file will never pass through an iPhone's audio stack or load cleanly into an Apple TV library.

AAC (Advanced Audio Codec) is the standard that replaced MP3 for most professional and consumer platforms. YouTube, Spotify, Apple Music, and iTunes all use AAC internally. It delivers better sound quality than MP3 at the same file size — a 128 kbps AAC file sounds closer to 192 kbps MP3. Android, iOS, macOS, Windows, and every major browser can decode it natively.

Extracting AAC from your MKV gives you a standalone audio file that drops into any modern ecosystem without friction. If the MKV already contains an AAC audio track, the converter can remux it directly without re-encoding, preserving the original quality exactly. If the source uses a different codec like AC3 or DTS, the audio is transcoded to AAC. File sizes are compact — typically 4–8 MB per minute at standard quality.

Quality & file size: MKV to AAC

Typical file sizes: MKV 200–800 MB → AAC 2–5 MB.

Both MKV and AAC use lossy compression. We transcode at high quality settings (equivalent to AAC's recommended web quality) to minimize generational loss.

Color depth: MKV supports standard color, AAC supports standard color.

Transparency: MKV does not support transparency. AAC does not support transparency — transparent areas become solid white.

Frequently asked questions

Privacy: how FormatDrop handles your files

Your MKVfiles are converted 100% inside your browser. They are never uploaded to our servers, never stored, and never seen by anyone other than you. This isn't a privacy policy claim — it's an architectural guarantee: our server has no endpoint that receives file bytes.