Trim MKV

How to Trim an MKV File Online

1. Upload Your MKV File: Drag and drop or click "Add Files" to select MKV (Matroska) videos — Plex / Jellyfin library rips, anime fansub releases, MakeMKV Blu-ray dumps, OBS recordings saved as MKV, or HDR remuxes. Multi-track MKVs with multiple audio languages, embedded subtitles, and chapter markers are all accepted. Batch is supported — drop in a season's worth of episodes at once.
2. Set Start Time and Duration (VIDEO_TRIM): Enter a start time and a duration to keep. Both fields accept seconds (12.5) or HH:MM:SS.sss format (00:21:45.500) for millisecond precision. Add multiple trim segments to extract several clips from one MKV in a single pass — useful for pulling every fight scene out of an anime episode or every goal out of a match recording.
3. Pick Output Settings (Optional): By default the trim is frame-accurate and the video is re-encoded at the visually-lossless default preset (CRF 18 for H.264 / CRF 17 for HEVC), keeping MKV as the container. Change the settings if you need a smaller file or a different codec: choose VIDEO_CODEC (H.264, H.265/HEVC, AV1, VP9, MPEG-2, MPEG-4, DivX, Xvid) or AUDIO_CODEC (AAC, AC3, EAC3, DTS, FLAC, Opus, Vorbis, MP3). Use VIDEO_RESOLUTION to scale (2160p, 1440p, 1080p, 720p, 480p, percentage, or custom width/height) and VIDEO_COMPRESSION for a quality preset (Highest → Lowest), CRF slider (18 = visually lossless for H.264/H.265, 23 = default, 28 = smaller; CRF 30 default for AV1/VP9), constant bitrate, or target file-size percentage.
4. Trim and Download: Click Trim. Files process on our servers — download individually or as a ZIP. No sign-up, no watermark, no length cap on the output. Multi-GB Blu-ray remuxes work fine.

Why Trim MKV Files?

MKV (Matroska) is the open-source container of choice for high-bitrate archival video — Plex and Jellyfin libraries, anime fansub releases, MakeMKV Blu-ray and UHD rips, HDR10/Dolby Vision remuxes, and any source where you want to preserve multiple audio languages, forced subtitles, and chapter markers in a single file. Trimming keeps just the section you mark: the kept range is decoded and re-encoded at the visually-lossless default preset, so the cut is frame-accurate and the clip stays true to the source. Common reasons to trim:

• Plex / Jellyfin library cleanup — Strip the 90-second studio idents, the 10-minute "previously on" recap before episode 1 of a season, or the post-credits stinger that breaks autoplay. The trimmed file stays MKV, so it drops straight back into your library.
• Anime episode trimming — Cut OPs and EDs from a 24-minute episode (the "skip intro" 90-second window), pull a single 30-second fight scene from a season, or split a 24-episode batch where each episode shares the same 1:30 OP cut point. Note the trim re-encodes to a single video and audio track — if you need every dub language and embedded ASS/SSA subtitle preserved, keep the source file alongside the clip.
• MakeMKV Blu-ray rips — A typical 2-hour Blu-ray remux is 25-40 GB. Trim to a single scene (a fight, a song, a director's commentary segment) instead of processing the whole thing — a 2-minute slice of a 35 GB UHD remux drops to a small fraction of the size.
• Multi-track recordings — OBS recordings saved as MKV often carry separate microphone, desktop audio, and game audio tracks. The trim re-encodes to a single mixed audio track, so if you need the separate stems for later mixing in DaVinci Resolve or Audacity, trim a working copy and keep the multi-track original.
• Sharing under email and chat caps — Gmail caps at 25 MB, Outlook at 20 MB, Discord at 10 MB free / 50 MB Nitro Basic / 100 MB Boost, WhatsApp at 16 MB. A 30-second trim plus optional re-encode brings most clips inside these limits — though for chat sharing you'll usually want to also convert to MP4 since Discord and WhatsApp don't preview MKV inline.
• HDR / Dolby Vision caveat — The trim re-encodes the video, and HDR10, HDR10+, and Dolby Vision metadata does not reliably survive a re-encode. If preserving the HDR layer matters, trim with a dedicated HDR-aware desktop tool and keep this page for SDR sources and quick shareable clips.

For a different output container after trimming, see MKV to MP4 (browser-friendly), MKV to WebM, or Compress MKV for size-only reduction without trimming.

Default Trim vs Custom Settings — When to Use Which

Property	Default settings	Custom settings
Speed	Proportional to clip length	Proportional to clip length and codec
Quality	Re-encoded at the visually-lossless preset (CRF 18 H.264 / CRF 17 HEVC)	Whatever CRF / bitrate you choose
Cut precision	Frame-accurate	Frame-accurate
Output codec	Standard codec in MKV	Any: H.264, H.265, AV1, VP9, MPEG-2/4, DivX, Xvid
Audio tracks	Single track, re-encoded at a matching bitrate	Re-encoded to the codec you pick
Subtitle / chapter / HDR metadata	Not guaranteed to survive the re-encode	Not guaranteed to survive the re-encode
Output size	Proportional to duration kept	Variable by CRF / bitrate
Best for	Quick clips at source-matching quality	Codec change, smaller file, different resolution

Keyframe layout doesn't limit the cut point: the kept segment is decoded and re-encoded, so cuts are frame-accurate (the exact frame a goal lands, the precise word in a podcast) regardless of whether the source is a 1-2 second GOP Blu-ray remux or a streaming-style file with keyframes every 5-10 seconds.

MKV Codec Quick Guide

Source codec	What the trim does	Notes
H.264 / AVC (most rips, OBS)	Re-encoded at the visually-lossless default (CRF 18)	Universally supported output
H.265 / HEVC (4K Blu-ray, anime)	Re-encoded at the visually-lossless default (CRF 17)	Keeps HEVC's size advantage; most Plex clients support
AV1 (modern re-encodes)	Re-encoded	~30% smaller than H.265, slower to encode
MPEG-2 (DVD rips in MKV)	Re-encoded; pick H.264 output to shrink 3-5×
AC3 / EAC3 (Dolby)	Audio re-encoded at a matching bitrate	Pick AC3/EAC3 output to keep a surround codec
DTS / DTS-HD MA	Audio re-encoded to a lossy codec	Lossless DTS-HD does not survive the trim
FLAC (audiophile rips)	Audio re-encoded (typically AAC)	Not bit-preserved — keep the original for archival
PGS subtitles (Blu-ray)	Not guaranteed to carry over	Extract subs separately if you need them

Frequently Asked Questions

Will trimming an MKV preserve all audio tracks and subtitles?

No — the trim re-encodes, and the output carries one video and one audio track. Lossless audio such as DTS-HD MA or FLAC comes out as a lossy codec (typically AAC unless you pick another), and secondary language tracks, commentary, and embedded subtitles are not guaranteed to carry over. For multi-track archival edits, use a desktop tool like MKVToolNix; use this page when you want a quick, frame-accurate clip and keep the multi-track source file intact.

Will HDR10 / HDR10+ / Dolby Vision metadata survive the trim?

Not reliably. The trim re-encodes the video, and HDR10/HDR10+ metadata and Dolby Vision RPUs generally do not survive a re-encode — expect the clip to come out as a standard SDR-range stream. The visually-lossless default preset still looks excellent on ordinary screens, but if triggering HDR mode on your TV is the point, trim with a dedicated HDR-aware desktop workflow and keep the untouched source.

What's the maximum MKV file size I can trim?

There's no fixed cap. Trimming runs on our servers, so the practical limit is upload size and connection speed and patience for the upload. 35 GB UHD remuxes from MakeMKV work — competitors like online-video-cutter.com cap at 4 GB on the free tier and 4 GB even on premium; XConvert does not. Processing time scales with the length of the segment you keep, not the full source duration.

Why does the cut start a few seconds earlier than I asked?

With XConvert it shouldn't — the trim re-encodes the kept segment, so the cut starts at your exact timestamp. The snap-back you're describing is how stream-copy cutters behave: they can only cut on keyframes (I-frames), and while Blu-ray remuxes use 1-2 second GOPs, streaming-style sources can have keyframes every 5-10 seconds, so those tools rewind to the nearest preceding keyframe. Here the cut is frame-accurate regardless of keyframe layout.

Can I trim an entire anime season in one batch?

Yes. Drop in all 24 episodes and apply the same start/duration (e.g., start 00:01:30 to skip the OP, duration 00:21:00 to keep the episode body). Per-file overrides are also supported if one episode has a slightly different OP length. All 24 trimmed files come back as a ZIP. This is dramatically faster than running through Avidemux or MKVToolNix per file, especially when each episode is a 1-2 GB 1080p file.

Will Plex / Jellyfin still scan and play the trimmed MKV correctly?

Yes. The trimmed file stays MKV with a standard codec, which Plex and Jellyfin scan and play like any other library file — direct play on Apple TV, Roku, Shield, and the web players depends on client codec support just as it did with the source. Watch out for naming — Plex matches files by filename pattern (Show Name - S01E01.mkv), so name your trimmed output the same as the source if you want metadata to auto-match.

Can I trim a Dolby Vision remux without losing the DV layer?

No — the trim re-encodes the HEVC stream, and the Dolby Vision RPU metadata (Profile 7 dual-layer on UHD Blu-ray rips, Profile 8 single-layer on streaming files) does not survive a re-encode. Preserving the DV layer through an edit requires specialized tooling (dovi_tool, custom ffmpeg builds). The trimmed clip still plays everywhere the source did, just without the DV layer — keep the untouched source if DV matters.

Should I trim first or convert to MP4 first?

Trim first, always. Trimming only processes the portion you keep, cutting the source from 30 GB down to just the segment you want. Running MKV to MP4 on a 30 GB remux is a much slower transcode than running it on the trimmed clip — far faster end-to-end. The same applies for Compress MKV — trim down to the segment you want, then compress only that segment.

What's the difference between trimming and cutting an MKV?

Same operation in practice. Some editors reserve "trimming" for shaving the start and end while keeping the middle, and "cutting" for extracting a middle portion or splitting at a point. XConvert handles all three patterns through the same start time + duration controls — for cut-style mid-clip extraction framing, see Video Cutter, which uses identical controls.