MKV to AVIF Converter

MKV to AVIF Converter

MKV (Matroska) is a video container, not an image — so converting it to AVIF means pulling a single frame out of the video and re-encoding that one picture as an AV1-coded still. AVIF is the modern web's most space-efficient image format, landing roughly 50% smaller than a JPEG at comparable visual quality. This tool captures the exact frame you choose — a poster image, thumbnail, or screenshot — rather than producing a looping animation. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

MKV Format at a Glance

AVIF Format at a Glance

How to Convert MKV to AVIF

1. Upload Your MKV File: Drag and drop your Matroska video onto the page or click "+ Add Files" to browse. MKV files are often large, so the main limit is upload size and time rather than anything on your device; batch is supported.
2. Choose a Frame Under Frame Selection: Pick Specific Frame and set Time (seconds) to the exact moment you want captured, or pick Multiple Screenshots and set a Capture Rate to grab a series of stills across the clip — each captured frame is saved as its own AVIF.
3. Set Quality Preset and Image Resolution: Leave Quality Preset on Very High (Recommended) for a near-lossless still, or switch to Specific file size to cap the output; use Image resolution to keep the original, apply a Preset Resolution, or set an exact Width × Height.
4. Convert and Download: Click Convert and save your AVIF image. No sign-up, no watermark.

Frequently Asked Questions

Does this produce a still AVIF or an animated one?

A still. Frame Selection defaults to Specific Frame, which extracts one picture at the timestamp you set and encodes it as a single AVIF. Multiple Screenshots saves a batch of individual stills — one AVIF per captured frame — not a looping clip. Animated AVIF tooling is still narrowly supported and most content systems treat AVIF as a still-image format, so if you want a looping output, an animated GIF or WebP is the more compatible choice.

Is the AVIF spec still maintained, and who owns it?

AVIF is defined by the Alliance for Open Media (AOMedia) — the same consortium behind the AV1 video codec, whose members include Google, Netflix, Mozilla, Amazon, and others. The AVIF image specification (v1.0.0) was published in 2019 and remains actively maintained; it stores an AV1 intra-coded image inside an ISOBMFF/HEIF container. Because AV1 is royalty-free, AVIF carries no licensing fees.

How much smaller is an AVIF frame than the same frame as JPEG?

In our testing, a 1080p frame extracted from an MKV and saved at the Very High preset typically came out 40–55% smaller than the same frame exported as a high-quality JPEG, with fewer blocking artifacts in skies and gradients. The exact ratio depends on scene complexity — flat, smooth frames compress the most, while grainy, detailed frames compress the least.

Which browsers and devices can open an AVIF file?

Roughly 93% of browsers in use today decode AVIF natively: Chrome 85+ (2020), Firefox 93+ (2021), Edge 121+ (2024), and Safari 16.4+ (macOS 13.3 / iOS 16.4, 2023). Older browsers and some desktop image viewers won't open it — if you need maximum compatibility, extract the frame as JPG instead.

Which version of the AVIF container does this output, and does it keep color depth?

The output is a standard single-image AVIF — an AV1 still inside an ISOBMFF/HEIF wrapper. AVIF can carry 8-, 10-, or 12-bit color, so a still pulled from a 10-bit MKV keeps smoother gradients than an 8-bit JPEG would. If you need a bit-perfect, lossless still with no compression at all, extract the frame as PNG instead.

What happens to the MKV's audio, subtitle, and chapter tracks?

They are dropped. A single-frame image can't hold audio, subtitle, or chapter streams, so only the picture data from the chosen frame is encoded. If you need those tracks intact, keep the MKV or convert it to another video container rather than to an image.

Why does AVIF encoding take longer than JPEG?

AVIF uses AV1's intra-frame compression, which is far more computationally expensive than JPEG's decades-old DCT approach. Extracting that extra efficiency from a single image takes real encoding work, so an AVIF still can take a few seconds where a JPEG is near-instant. The payoff is a smaller file at matching quality.

Are my files uploaded to a server, and how long are they kept?

Yes — the MKV is decoded and the chosen frame is encoded to AVIF on our servers, not in your browser. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours. There is no sign-up, no watermark, and files are never shared or made public.