Cut MKV

How to Cut MKV Files Online

1. Upload Your MKV File: Drag and drop or click "+ Add Files" to select Matroska clips from your device. Batch processing is supported, so you can queue several rips at once.
2. Set Start and Duration: In the Trim group, enter the start timestamp (HH:MM:SS or seconds) and either the duration or end time of the segment you want to keep. Multiple segments per file are supported when you re-add the source.
3. Adjust Codec and Quality (Optional): Leave the settings untouched and the cut is frame-accurate, re-encoded at the visually-lossless default preset. Otherwise pick a Video Codec (H.264, H.265, VP9, AV1), choose a Quality Preset, or set a CRF value (lower = higher quality). You can also constrain by Video Bitrate or pick a Resolution Preset (e.g. 1080p, 720p).
4. Cut and Download: Click "Cut". 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.

Why Cut MKV Files?

Matroska (.mkv) is an open, royalty-free container based on EBML, announced on 6 December 2002 and now the de-facto wrapper for Blu-ray rips, anime releases, and home-server libraries. A single MKV can carry unlimited video, audio, subtitle, picture, and chapter tracks in one file — which makes it powerful, but also makes it the wrong shape for short shares, social posts, or quick previews. Cutting a clean segment out of a 12 GB rip is usually the first step toward almost anything else.

• Trim Blu-ray and DVD rips — Pull the actual feature out of a MakeMKV dump that includes trailers, FBI warnings, studio logos, and chapter previews. A 40 GB raw disc rip typically contains only ~2 hours of usable content.
• Share an anime moment without re-uploading the episode — Cut a 30-second scene from a fansub MKV. Note the cut re-encodes to a single video and audio track, and soft ASS subtitle tracks aren't guaranteed to carry over — keep the source episode if the typesetting and karaoke effects matter.
• Make a YouTube-ready clip — Extract a single play from a sports broadcast or a single demo from a conference recording. YouTube accepts MKV but you'll often want to also cap length and drop unused audio tracks at the same time.
• Prep clips for Plex or Jellyfin testing — Slice a 90-second sample to reproduce a transcoding issue, then upload to a GitHub issue. Image-based subtitles like PGS force a full transcode in Jellyfin, and a tiny reproducer is far easier to debug than the whole movie.
• Pull intros, outros, or bumpers — Save the cold open of a TV episode or the credit sequence from a film for editing into a montage, at source-matching quality.
• Cut training-data clips for ML or computer vision — Researchers often need 5-10 second action segments from longer surveillance, sports, or driving footage; MKV's chapter metadata makes finding the right window faster.

MKV vs MP4 vs WebM — Container Comparison

Property	MKV (Matroska)	MP4 (ISO BMFF)	WebM
First released	2002 (Matroska project)	2001 (MPEG-4 Part 14)	2010 (Google)
Standards body	matroska.org (open, royalty-free)	ISO/IEC 14496-14	WebM Project (subset of Matroska)
Allowed video codecs	Virtually any (H.264, H.265, AV1, VP9, ProRes, FFV1)	H.264, H.265, AV1 (plus more in practice)	VP8, VP9, AV1 only
Allowed audio codecs	Virtually any (AAC, AC-3, DTS, FLAC, Opus, TrueHD)	AAC, MP3, Opus (varies by player)	Vorbis, Opus only
Subtitle support	SRT, SSA/ASS, WebVTT, PGS, VobSub, USF	Limited (TX3G, WebVTT)	WebVTT only
Chapters	Yes, native	Yes, native	Yes, inherited from Matroska
Multiple audio/subtitle tracks	Unlimited	Yes, but tooling is weaker	Yes
HTML5 <video> playback	Not natively supported in any major browser	Universally supported	Chrome, Firefox, Edge, Opera; Safari since 14.1 (macOS 11.3+)
Typical use	Blu-ray rips, anime, archival masters	Phones, web, social, editing	Web video, ads, YouTube alt-source

Cutting Approaches — and Which One This Tool Uses

Mode	What it does	Speed	Quality	Trade-off
Stream copy (some desktop tools)	Demuxes and remuxes the existing video/audio packets	Very fast (10-100× real time)	Identical to source	Cut points snap to the nearest keyframe (often 1-10 seconds away from your target)
Smart cut (rare tooling)	Re-encodes only the GOP at each cut edge, copies the rest	Medium	Near-lossless; one re-encoded keyframe per edge	Tooling support is limited; some codec combinations don't allow it
Full re-encode (how XConvert cuts)	Decodes and re-encodes every frame between your cut points	Proportional to clip length	Visually lossless at the default preset	Frame-accurate cuts; one generation of compression that's visually indistinguishable at the defaults

XConvert always uses the re-encode path: leave the Codec and Quality settings untouched and the cut is re-encoded at the visually-lossless default preset, frame-accurate to your timestamps. Pick a codec or CRF only if you also want to recompress or change container compatibility (for example, converting to MP4 for iPhone or social sharing).

Frequently Asked Questions

Why does my MKV cut not start exactly where I asked?

With XConvert it should — the cut re-encodes the kept segment, so the output starts exactly at your requested timestamp. The snapping you may have seen elsewhere comes from stream-copy tools: H.264, H.265, VP9, and AV1 all use inter-frame compression, so a tool that cuts without re-encoding can only split at keyframes — and a 1080p Blu-ray rip typically has one keyframe every 1-10 seconds. Here the keyframe layout doesn't affect the cut point.

Will all my audio tracks and subtitles be preserved?

No — the cut re-encodes, and the output carries one video and one audio track. Lossless audio such as DTS-HD or FLAC comes out as a lossy codec (typically AAC unless you pick another), and subtitle tracks (SRT, SSA/ASS, PGS Blu-ray subs) are not guaranteed to carry over. For multi-track archival edits use a desktop tool like MKVToolNix; use this page for a quick, frame-accurate clip and keep the multi-track source intact.

Can I cut multiple segments from one MKV in a single pass?

Yes — re-add the same source file for each segment you want, set distinct start/duration values per copy, and queue them together. Each output is a separate trimmed MKV. To stitch the segments back into one file afterwards, use mkvmerge --append from MKVToolNix or the equivalent FFmpeg concat demuxer locally.

What's the difference between cutting MKV and cutting MP4?

The mechanics are identical at the codec level (both are decoded and re-encoded the same way), but MKV as a container supports features that MP4 can't carry cleanly: PGS subtitles, multiple lossless audio tracks like DTS-HD MA or TrueHD Atmos, and rich chapter metadata. If you cut an MKV then convert it to MP4, you may lose subtitle tracks the destination container doesn't support. If you only need MP4 from the start, cut MP4 directly.

Why won't my cut MKV play in Chrome or Safari?

No major browser natively supports the MKV container in the HTML5 <video> tag, even when the inside codecs are H.264/AAC that the browser can decode. To play in a browser, either install a player like VLC or convert the trimmed output to MP4 or WebM. Note that WebM is technically a subset of Matroska — same EBML structure, but restricted to VP8/VP9/AV1 video and Vorbis/Opus audio so browsers can guarantee playback.

Does cutting an MKV reduce quality?

Not visibly. The cut decodes the kept segment and re-encodes it at the visually-lossless default preset, so the output is not mathematically identical to the source but is visually indistinguishable from it. The upside is that the cut is frame-accurate. Quality only drops noticeably if you deliberately select a lower Quality Preset or a higher CRF/lower bitrate.

Can I keep MKV chapters when cutting?

Not reliably — the cut re-encodes the streams, and chapter markers are not guaranteed to carry into the output (chapters outside the cut window are gone in any case). If chapter-preserving edits matter, use MKVToolNix locally, where chapters can be rebased and re-muxed explicitly.

Will the file size scale with the cut length?

Roughly, yes. The default preset re-encodes near the source quality level, so cutting a 60-minute, 8 GB H.265 MKV down to 6 minutes lands in the ballpark of an 800 MB file (the exact size varies with content complexity). If the result is still too large for your destination (Discord's 10 MB free cap, Gmail's 25 MB attachment limit, or a 100 MB upload form), follow up with Compress MKV to lower the bitrate, or convert to a more efficient codec.

How is this different from MKVToolNix or LosslessCut?

Both are excellent desktop tools — MKVToolNix is the reference muxer for the format, and LosslessCut wraps FFmpeg with a friendly UI for keyframe-snapped stream-copy trims. xconvert runs an FFmpeg-grade pipeline on our servers and re-encodes the kept segment at the visually-lossless default, trading byte-identity for frame-accurate cuts and nothing to install; very large rips (10+ GB) are still faster in a native desktop tool that can use your full SSD bandwidth.