Convertto

100% free online local file conversion, no limits, no uploads.

Source Format
.mkv

About MKV

The Matroska (MKV) multimedia container was launched in Russia in 2002 as a completely open-source project. Its name is derived from the Russian Matryoshka nesting dolls, symbolizing its ability to wrap an unlimited number of data tracks inside a single file.

MKV is highly appreciated by video enthusiasts because it supports advanced subtitles (ASS/SRT), multi-language audio tracks, and chapter menus. It is the premier container for high-fidelity movie backups and multi-track media files.

Output Format
.flac

About FLAC

The Free Lossless Audio Codec (FLAC) was introduced in 2001 as an open-source format for lossless audio compression. Unlike MP3 or AAC, FLAC compresses audio files without discarding any digital waveform data, providing bit-for-bit accuracy to the original source.

FLAC files are typically 50% smaller than raw WAV recordings, making them highly desirable for audiophiles, digital collectors, and archiving projects where compromising sound quality is not an option.

Format Comparison: MKV vs FLAC

Side-by-side technical capabilities comparison between MKV and FLAC files.

SpecificationMKV DetailsFLAC Details
Full NameMatroska Video FileFree Lossless Audio Codec
CategoryVideoAudio
CompressionLossy or LosslessLossless
TransparencyNoN/A (Audio)
AnimationYesN/A (Audio)
Audio SupportYes (Virtually any audio codec)Yes (Lossless multi-channel)
Video SupportYesNo
Metadata TagsYes (Matroska tags, XML properties)Yes (Vorbis Comments, cuesheets)
Typical File SizeMedium to LargeMedium
Best Used ForMovies, multi-language videos, high-definition video collectionsAudiophile music archiving, high-quality audio storage

What happens during .mkv to .flac conversion?

Our tool extracts the raw audio stream directly from your MKV video container, discarding all visual picture frames. This produces a high-fidelity, pure FLAC audio file without any uploaded traffic or degradation of sound details.

This conversion happens 100% locally in your browser. No files are uploaded to any server.
  • Audio Converter

    • Supports MP3, WAV, FLAC, OGG, AAC & M4A
    • Extract high-quality audio from any video file
    • Generate visual waveforms for audio-to-image
  • Video Converter

    • Transcode MP4, WebM, AVI, MOV & MKV
    • Advanced browser-based compression tools
    • Frame-accurate format conversion technology
  • Image Converter

    • WEBP, PNG, JPG, GIF, SVG, BMP, ICO & TIFF
    • Batch convert images to video slideshows
    • High-speed browser-native processing
  • Document Converter

    • Professional PDF to Video creation (10s per slide)
    • Secure DOCX to PDF & high-quality Image exports
    • Local-first Image to PDF batch compilation
  • Privacy & Security

    • 100% local processing—files never leave your PC
    • Browser-sandboxed for maximum data security
    • No server storage, data logging, or tracking
  • Unlimited & Local

    • No subscription or daily conversion limits
    • Works on Windows, macOS, Linux & Mobile
    • Convert up to 30 files in a single local batch

Frequently Asked Questions

Everything you need to know about our secure file converter.

Are my files uploaded to a server?
No. Your files never leave your computer. Free Convert To uses browser-native technology (WebAssembly + FFmpeg) to process everything locally. This ensures your data remains 100% private and secure.
Do I have to sign up or create an account?
No! Free Convert To is completely open and accessible to everyone. There is no sign up, no email required, and no account creation. You can start converting files immediately.
Are there any file size limits?
We do not impose any artificial file size limits. Since the conversion happens locally on your device, the only limit is your available system RAM.
What file formats are supported?
We support a comprehensive list of formats.
  • Audio: MP3, WAV, FLAC, OGG, AAC, M4A, OPUS.
  • Video: MP4, WebM, AVI, MOV, MKV, GIF.
  • Image: WEBP, PNG, JPG, JPEG, SVG, BMP, ICO, TIFF, HEIC.
  • Document: PDF, DOCX.
Can I convert PDF to video?
Yes! You can convert any PDF document into a video file. Our tool will automatically treat each page as a slide and assign it a 10-second duration in the resulting video.
Can I convert DOCX to PDF or Images?
Absolutely. You can convert Microsoft Word (DOCX) files to high-quality PDF documents or extract the pages as individual images, all within your browser.
Can I convert image to audio?
Yes! You can convert any static image into an audio file. The tool will use your image as the album art for the resulting audio track.
Can I convert video to image?
Yes! You can extract high-quality frames from any video file and save them as images (PNG, JPG, WEBP), or convert short clips into animated formats like GIF.
Can I convert audio to image?
Yes! Our tool can analyze your audio file and generate a professional visual waveform, which is then saved as a high-resolution PNG or JPG image.
Can I convert video to audio?
Absolutely. You can extract the original audio track from any video file and save it in formats like MP3, WAV, or FLAC without any quality loss.
Can I convert multiple files at once?
Yes! You can drag and drop multiple files to batch process them. Our tool supports converting up to 30 files in a single session.
How many conversions can I do per day?
There are no limits. You can perform as many conversions as you need, 24/7. We do not have any daily, hourly, or monthly caps.
Does it work offline?
Once the initial page and conversion engine are loaded, the actual file processing happens entirely on your local machine. This means you don't need a constant high-speed connection while your files are being converted.
Is my data shared with third parties?
Never. Because your files are never uploaded to any server, it is physically impossible for us or any third party to access, see, or share your data.
What happens to my files after conversion?
Your files remain exactly where they are—on your computer. We don't store them, so there is no need to 'delete' them from our side. Once you close the tab, all temporary processing data is wiped from your browser's memory.

Loved by users worldwide

Join thousands of people who convert their files securely every day.

"Finally a converter that doesn't ask for my email! Super fast and the privacy factor is huge for me."

Sarah J.
Sarah J.Graphic Designer

"The video to audio extraction is flawless. I use it for my podcast clips every day."

Mark T.
Mark T.Content Creator

"I was skeptical about 'browser-only' conversion but it handled my 500MB video without a hitch."

Elena R.
Elena R.Software Engineer

"The UI is so clean. No ads popping up everywhere, just a solid tool that works."

David W.
David W.Marketing Manager

"Converting HEIC to JPG for my work projects is now a one-click task. Highly recommended!"

Chloe M.
Chloe M.Photographer

"Batch processing 20 files at once saved me so much time. Truly unlimited."

James L.
James L.Video Editor

"Great tool, would love to see more obscure audio formats added in the future, but for 99% of tasks it's perfect."

Alex K.
Alex K.Student

"Very fast and secure. Sometimes the first load takes a few seconds but once it's ready it's instant."

Maria S.
Maria S.Freelancer