MKV to AV1 Converter

How to Convert MKV to AV1 Online

1. Upload Your MKV File: Drag and drop or click "Choose Files" to add a Matroska (.mkv) video. Batch uploads of multiple MKV files are supported and each is processed independently.
2. Pick Video Codec and Audio Codec: Video Codec defaults to AV1 (this is the whole point — re-encoding the inner stream from H.264/HEVC/VP9 into AV1). Audio Codec defaults to Opus, which pairs naturally with AV1 since both are royalty-free Alliance for Open Media codecs. Switch the audio dropdown to AAC if your target player is older or to FLAC if you want to preserve a lossless source track.
3. Set Quality (Optional): Under File Compression pick one of: Quality Preset (Lowest through Highest, with Very High recommended), Specific file size in KB/MB, Constant Bitrate or Variable Bitrate in kbps/Mbps, or Constant Quality which exposes a CRF slider on AV1's 0-63 scale (default 30, lower = sharper).
4. Resize, Trim, and Convert: Under Video Resolution choose Keep original, a Preset Resolution (4K, 1440p, 1080p, 720p, 480p, etc.), Resolution Percentage, or set Width/Height/Width x Height directly. Under Trim, switch from Unchanged to Time Range and enter a Start time and Duration to cut a segment. Click Convert — files process on our servers with no sign-up and no watermark.

Why Convert MKV to AV1?

MKV (Matroska) is a flexible open container that wraps almost any video and audio codec along with multiple subtitle tracks and chapters. The container itself does not compress — the codec inside does, and most large MKV files in the wild ship H.264, HEVC, or VP9 video. Re-encoding to AV1, finalized by the Alliance for Open Media in June 2018, typically cuts file size meaningfully versus HEVC at the same perceived quality (Netflix and YouTube both publish their own internal numbers in this range), with even larger savings versus older H.264 source.

• Shrink a movie library — A 4-8 GB H.264 1080p MKV rip will often compress to 2-4 GB at AV1 CRF 28-32 with no visible quality loss on a TV-distance viewing setup.
• Stream-ready encodes — YouTube, Netflix, Twitch, and Meta all distribute AV1 in production today; pre-encoding to AV1 means the platform's own re-encode is a passthrough or a lighter pass.
• Future-proof archives — AV1 is royalty-free under AOMedia's patent license and is the codec major streamers are standardizing on for the 2020s, the way H.264 dominated the 2010s.
• Web delivery on a budget — Lower bitrates at the same SSIM/VMAF mean less CDN egress; AV1 is a budget item, not just a quality item.
• Pair with Opus audio — Opus is the default and a strong match: it beats AAC at low bitrates and is unrestricted by patents, keeping the entire output royalty-free.
• Single-track output for finicky players — Source MKVs often pack 5-10 subtitle tracks and multiple language audio streams; the converter outputs one clean video + audio stream, which sidesteps a lot of player compatibility weirdness.

MKV (Source) vs AV1 Output — Format Comparison

AV1 Hardware Decode — What Plays Smoothly in 2026

Without hardware decode, AV1 falls back to CPU; modern desktop CPUs handle 1080p AV1 fine in dav1d, but 4K AV1 software decode on older laptops or budget mobile chips can struggle. If you need to play back on a Plex server that doesn't yet pass AV1 through to the client, transcode there or stick with HEVC for now.

Frequently Asked Questions

Why is AV1 encoding so much slower than H.264 or HEVC?

AV1 packs more compression tools into every frame — far more partitioning options, more reference frame configurations, and tighter inter-prediction. The reference encoder libaom is the slowest; libsvtav1 (Intel/Netflix/AOMedia) is dramatically faster and is what most production pipelines use today. Even at fast presets, expect AV1 encoding to run a multiple slower than x264 on the same machine. The trade-off is the resulting file plays the same on the same hardware as an H.264 file — only the encode is expensive, not the decode.

What CRF should I pick for AV1?

CRF 30 is the default and a sensible starting point for general 1080p content. CRF 23-27 keeps near-source quality on detailed material (animation, fine grain, dark scenes); CRF 32-36 shrinks files aggressively for casual viewing or web preview. The 0-63 scale is wider than H.264/HEVC's 0-51, so don't reuse your x264 numbers directly — AV1 CRF 30 is roughly equivalent in perceived quality to x265 CRF 24-26.

Will my MKV's subtitle and chapter tracks survive the conversion?

The converter outputs a single video + audio stream, so multiple subtitle tracks and chapter markers in the source MKV are not carried into the AV1 output by default. If you need the subtitle track in the final file, burn it into the video at upload (some players let you pre-select the track) or keep it as a sidecar .srt file alongside the AV1 video.

Why is Opus the default audio codec instead of AAC?

Opus is the natural pairing for AV1 — both are royalty-free AOMedia/IETF codecs, and Opus outperforms AAC at low and medium bitrates in listening tests (it is the standard codec for WebRTC and Discord voice for the same reason). AAC remains the right choice if your target playback device is older, since AAC is universally supported while Opus is mostly playable on modern browsers, smart TVs, and 2020+ media players.

Does AV1 work on iPhone, iPad, or macOS?

Hardware decode landed in Apple silicon with the M3 family of Macs (October 2023) and the iPhone 15 Pro / Pro Max (A17 Pro). The M4 iPad Pro and the entire iPhone 16 lineup also decode AV1 in hardware. Older Apple devices (M1/M2 Macs, iPhone 14 and earlier, iPads pre-M4) play AV1 in software inside browsers like Chrome and Firefox — fine for short 1080p clips, painful for long 4K HDR.

Should I convert an MKV that's already HEVC?

It depends on your goal. For pure storage savings you'll typically save another 20-30% going from HEVC to AV1, but you spend a slow CPU-bound re-encode and a small amount of generational quality loss to do it. For streaming readiness or future-proofing a master archive, the conversion is worth it; for casual viewing where HEVC already plays everywhere you care about, leave it alone.

Can I batch-convert a folder of MKVs at once?

Yes — drop multiple.mkv files onto the upload area and each one converts independently with the same Video Codec / quality / resolution settings. AV1 encodes are CPU-heavy, so a batch of long 4K movies will take noticeably longer than a single file; queue overnight if you're re-encoding a whole season.

How do I trim out one scene during the conversion?

Switch the Trim option from Unchanged to Time Range, enter a Start time in HH:MM:SS.mmm format, and set a Duration. The encoder reads only the requested range and produces an AV1 file containing just that segment — no separate cut-then-encode pass needed. For multiple non-contiguous segments, run the conversion once per segment.

What if I want MKV-to-MKV with AV1 inside, not a raw.av1 stream?

For most playback workflows that's actually what you want, since players consume Matroska containers more reliably than raw AV1 bitstreams. Use Convert MKV to MKV and select AV1 as the Video Codec — the result is an MKV file whose internal video is AV1 + Opus, ready for VLC, mpv, Plex Direct Play on supported clients, and any modern smart TV. Or for the reverse direction, see AV1 to MKV.