Trim AV1

How to Trim AV1 Video Online

1. Upload Your AV1 File: Drag and drop or click "Add Files" to select AV1 video. Files in .mkv, .mp4, or .webm containers carrying an AV1 stream all work. Batch is supported — drop in multiple clips.
2. Set Time Range: Under "Trim," choose Time Range and enter Start (HH:MM:SS.ms) and Duration. The output keeps only the segment you specify; everything outside is discarded.
3. Pick Compression (Optional): Default is Quality Preset (Highest → Lowest). Switch to Constant Quality for CRF (AV1 uses a 0-63 scale — 23-30 is the visually lossless sweet spot, lower means larger / higher quality), or target a specific output by Constant Bitrate, Variable Bitrate, Target file size (%), or Specific file size in MB / GB. AV1's range and tuning differ from H.264 — see the CRF guide below.
4. Resize and Trim (Optional): Under "Video resolution," keep original, pick a preset (2160p / 1440p / 1080p / 720p / 480p), enter custom width × height, or scale by percentage. Click Trim to download the clip — files process in your browser session, no sign-up, no watermark.

Why Trim AV1 Files?

AV1 (AOMedia Video 1) is the open, royalty-free video codec finalized in June 2018 by the Alliance for Open Media — backed by Google, Netflix, Amazon, Microsoft, Apple, Mozilla, Intel, AMD, and Nvidia. It typically delivers ~30% better compression than VP9 and ~50% better than H.264 / x264 at equivalent quality, which is why YouTube already serves more than 75% of its catalog in AV1 and Netflix reports ~30% of streams using it. Most AV1 files arrive as .mkv, .webm, or AV1-in-.mp4 recordings from screen capture tools, YouTube re-downloads, or modern encoders like SVT-AV1 and aomenc. Common reasons people trim them:

• Cutting clips from YouTube / Twitch downloads — A 1-hour streamed VOD pulled at AV1 4K is often 2-4 GB. Trimming a 90-second highlight keeps the file tiny while staying in AV1.
• Removing dead time from screen recordings — OBS Studio added AV1 recording in 30.0 (2023). Trimming the boot-up and shutdown frames keeps the file small without re-encoding the whole capture.
• Sharing on AV1-aware platforms — Discord, Twitter/X, and YouTube all play AV1 in modern browsers; sending a 30-second AV1 clip avoids the ~2× size hit of converting to H.264 just to share.
• Game capture and replay clips — NVIDIA RTX 40 series and Intel Arc GPUs encode AV1 in hardware; trimming the highlight from a 10-minute capture keeps the file under 100 MB while preserving fine motion detail.
• Archiving only the parts you need — AV1 is the most space-efficient codec in mainstream use. Trimming before archival multiplies that win — a 5-minute keepable section from a 2-hour recording occupies <5% of the original disk space.
• Preparing previews for AV1-encoded media libraries — Trim a 30-second sample to verify a Plex / Jellyfin AV1 transcode looks right before committing the full encode.

AV1 vs Other Modern Video Codecs

Property	AV1	H.265 / HEVC	H.264 / AVC	VP9
Compression vs H.264	~50% smaller	~40% smaller	Baseline	~30% smaller
Royalty / licensing	Royalty-free (AOMedia)	Patent pool (MPEG LA, others)	Patent pool (MPEG LA)	Royalty-free (Google)
Spec finalized	June 2018	2013	2003	2013
Browser playback	Chrome 70+, Firefox 67+, Edge 121+, Safari 17+ (HW only)	Safari, Edge; partial elsewhere	Universal	Chrome, Firefox, Edge
Hardware decode	Intel 11th gen+, AMD RDNA 2+, Nvidia RTX 30+, Apple A17 Pro / M3+, Snapdragon 8 Gen 1+	Widespread since ~2017	Universal since ~2010	Limited HW; broad SW
Encoding speed	Slow (still ~5-10× H.264 even with SVT-AV1)	Medium	Fast	Medium
Typical use	YouTube, Netflix, Twitch streams; future archival	Apple ecosystem, modern TVs, Plex / Jellyfin	Universal compatibility	YouTube fallback, WebM

Sources: caniuse.com/av1, Wikipedia: AV1.

AV1 CRF Reference (0-63 scale)

CRF	Visible loss	Typical 1080p result	Best for
18-22	None — visually lossless	Larger than H.265 CRF 18 equivalents	Archival masters, mastering passes
23-27	Imperceptible on TV / monitor	~30-50% smaller than H.264 CRF 18	Streaming masters, clean library re-encodes
28-32	Subtle on critical content	Sweet spot for shareable clips	YouTube / Twitch uploads, social sharing
33-40	Visible on motion / gradients	Aggressive	Mobile previews, low-bandwidth distribution
45+	Heavy artifacting	Last resort	Thumbnail-grade previews only

Note: AV1's CRF scale (0-63) differs from H.264 / H.265 (0-51). Roughly, AV1 CRF 30 ≈ H.264 CRF 23 for similar visual quality, but actual mileage depends on content.

Frequently Asked Questions

Does trimming re-encode the AV1 stream?

The xconvert trimmer re-encodes the trimmed segment to honor your compression / resolution settings — that gives flexible cut points and clean output regardless of where keyframes (I-frames) fall. AV1 encoding is slower than H.264 or H.265, so expect longer processing on long clips. If you only want to cut at exact keyframe boundaries with zero quality loss, command-line tools like ffmpeg -c copy are an alternative, but those constrain your cut points to GOP boundaries.

Why is AV1 trimming slower than MP4 trimming?

AV1 encoding is computationally heavier than H.264 / H.265 by design — the same coding tools that produce ~50% smaller files also take longer to compute. SVT-AV1 (the open-source encoder behind most AV1 services) has closed much of the speed gap since 2023, but encoding remains slower than x264. If speed matters more than file size, convert AV1 to MP4 with H.264 first, then trim — the H.264 trim runs faster but the file will be ~2× larger.

What devices and browsers play AV1 today?

Per caniuse.com/av1, about 94% of users have AV1-capable browsers. Chrome 70+, Firefox 67+, Edge 121+, Opera 57+, and Samsung Internet 12+ all play AV1. Safari 17+ plays AV1 only on hardware-decode capable Apple silicon — iPhone 15 Pro / 16 family, Macs with M3 / M4, and the M4 iPad Pro. Older Apple devices on Safari 17 do not play AV1 (Apple ships no software fallback). For hardware decode on PCs, Intel 11th gen, AMD RDNA 2, and Nvidia RTX 30 series and newer GPUs handle it natively.

Should I keep my output as AV1 or convert to MP4 / H.264?

Keep AV1 if your audience is on modern browsers / phones and you value the smaller file size — half the bytes of equivalent H.264. Convert to MP4 with H.264 if you need playback on older TVs, set-top boxes, hardware video editors, or pre-2022 phones — H.264 plays on essentially every device made in the last 15 years. For a middle ground, convert AV1 to HEVC keeps most of the size advantage while gaining Apple-ecosystem compatibility.

Will the audio track survive trimming?

Yes — audio tracks (commonly Opus, AAC, or Vorbis inside MKV / WebM / MP4 containers carrying AV1) are kept and synchronized to the trimmed video. Multi-track audio in MKV / WebM survives by default; if you re-target an MP4 container, only the first audio track is preserved.

What container should I use — MKV, WebM, or MP4?

Per Wikipedia, AV1 is supported in MP4, WebM, and Matroska (MKV). WebM is the native pairing for browser streaming and the original AOMedia reference container. MKV is best for local libraries with subtitles / multi-audio (Plex, Jellyfin). MP4 is the most broadly compatible — choose it if you'll share the file with apps that don't recognize WebM. xconvert preserves the original container by default.

Can I trim and compress in a single pass?

Yes. Trim sets the time range; the compression options (Quality Preset, CRF, Target file size, etc.) apply to the output. Trimming first cuts the most weight — a 30-second cut from a 5-minute clip is already 90% smaller before any encoder tuning. For more aggressive compression of longer clips, see Compress AV1.

How precise are the cut points?

Time inputs accept hours, minutes, seconds, and milliseconds (HH:MM:SS.ms). Re-encoding the segment lets the trimmer cut at frame-accurate boundaries rather than rounding to the nearest keyframe. For a 60 fps source you can position cuts to ~16 ms precision (one frame).

Why is my AV1 file still larger than I expected?

AV1 outperforms H.264 by a wide margin, but small clips, fast motion, or grainy / film-grain content compress less efficiently. Try lowering CRF cautiously (28-32 is usually optimal), drop resolution to 1080p / 720p if archiving from 4K, or set a Target file size. If you need a specific cap, switch to "Specific file size" and the encoder will auto-scale bitrate to hit it.