Cut AV1 Video

How to Cut an AV1 Video Online

1. Upload Your AV1 File: Click "Choose Files" or drag your AV1-encoded clip into the drop zone. Files run through your browser session — no upload to a long-term server, no sign-up, no watermark. Batch is supported if you need to cut several clips with the same settings.
2. Set Start Time and Duration: Open Trim and enter a Start Time and a Duration. Both accept seconds (e.g. 12.5) or HH:MM:SS.sss (e.g. 00:01:30.250). Duration is the length of the kept segment, not the end timestamp — set Start 00:00:30 + Duration 00:02:00 to keep the 30s–2m30s window.
3. Tune Codec, Quality, and Resolution (Optional): Under Video Codec the default is AV1 (re-encoded with libaom/SVT-AV1 via FFmpeg); under Audio Codec the default is Opus. File Compression exposes Quality Preset (Highest → Lowest), Target File Size %, Specific File Size (MB/KB), Constant Bitrate, Variable Bitrate, Constant Quality (CRF, 0–63 for AV1) and Constraint Quality. Video Resolution defaults to Original; switch to a Preset (4K, 1440p, 1080p, 720p, 480p, 360p, 240p, 144p), a Fixed Resolution, a percentage, or a custom Width×Height.
4. Cut and Download: Click "Convert." The trimmed AV1 file downloads when processing finishes — usually a few seconds for short web clips, longer for high-resolution sources because AV1 re-encoding is computationally heavy.

Why Cut AV1 Video?

AV1 is the royalty-free video codec finalized June 25, 2018 by the Alliance for Open Media (Google, Mozilla, Netflix, Amazon, Microsoft, Cisco, Intel, plus later additions including Apple, AMD, Nvidia, and Samsung). It targets roughly 30% better compression than H.265/HEVC at equivalent visual quality, which is why Netflix, YouTube, and Meta have shifted significant streaming volume onto it. Cutting AV1 is usually about taking a long source — a YouTube download, an OBS recording, a Netflix-style screener — and pulling out a usable clip without ballooning the file by re-encoding to H.264.

• Trim a long screen recording for sharing. OBS Studio, Shadowplay, and AMD ReLive all support AV1 capture on hardware encoders (RTX 40-series, Arc, RDNA 3+). Cut the relevant 30-second moment instead of uploading an hour of footage to Discord, Slack, or Drive.
• Strip intros, sponsor reads, or credits. AV1 archives from YouTube/Twitch downloaders often include 10–30 seconds of intro graphics; removing them keeps the file smaller and the message sharper.
• Extract a clip for a social post. Reels (AV1 since November 2022), YouTube Shorts, and X video posts all play AV1 on supporting clients. Cut a 15–60-second segment without re-uploading the full file.
• Pull a reference still or proof. Cut to a 1–2-second segment around the frame you need, then export a single frame downstream — useful for QA on encoder ladders or for evidence/incident clips.
• Build a highlight reel. Cut the AV1 source into segments first (each ~10–30 seconds), then concatenate downstream. Cutting before stitching keeps each segment's bitrate behavior predictable.
• Reduce file size without changing codec. A 5-minute AV1 clip at the same CRF is usually 1/3 the size of the 15-minute original — pure trim is the cheapest way to shrink AV1 when you don't want to re-encode at a lower quality.

AV1 Codec — Spec at a Glance

Property	Value
Standard	AV1 v1.0.0 (Alliance for Open Media, June 2018)
Family	Royalty-free, successor to VP9
Compression vs H.265	~30% smaller files at equivalent quality
Reference encoders	libaom (BSD), SVT-AV1 (Intel/Netflix), rav1e (Xiph)
Common decoder	dav1d (VideoLAN) — used by Chrome, Firefox, VLC
CRF range	0–63 (lower = higher quality; AV1 uses a wider scale than H.264's 0–51)
Default audio pairing	Opus (royalty-free, AOMedia-aligned)
Common containers	MP4 (ISOBMFF binding), MKV, WebM
Hardware decode	Intel Arc, RTX 30/40-series, AMD RDNA 2+, Apple M3+
Hardware encode	Intel Arc, RTX 40-series, AMD RDNA 3+
Browser support	Chrome 70+, Firefox 67+, Edge 121+, Opera 57+, Safari 17.0+ (partial)
Major streaming use	Netflix (~30% of streams, Dec 2025), YouTube (8K AV1), Meta Reels

Cut Targets and Settings Cheat Sheet

Goal	Start Time	Duration	Recommended compression
Remove a 15s intro from a 5-min clip	00:00:15	00:04:45	Quality Preset = High
Pull a 60s teaser	00:02:00	00:01:00	CRF 28–32 (Constant Quality)
Keep first 10 minutes only	00:00:00	00:10:00	Variable Bitrate (matches source)
Sub-second precise frame slice	00:00:12.500	00:00:00.500	Quality Preset = Highest
Shrink a 4K AV1 archive to 1080p clip	00:00:00	(whatever you keep)	Resolution Preset = 1080p, CRF 32

Frequently Asked Questions

Does cutting AV1 here re-encode the file?

Yes — XConvert re-encodes the trimmed segment through FFmpeg's AV1 encoder. That gives you frame-accurate Start/Duration and lets you change codec, bitrate, or resolution in the same pass, but it is not the same as "lossless cut" tools like LosslessCut or SolveigMM Video Splitter, which copy the original AV1 stream without re-encoding (faster, but only on keyframe boundaries). If preserving every original bit matters more than millisecond precision, use a lossless cutter instead.

Why is the CRF range 0–63 instead of 0–51?

AV1 (and VP9) inherit their quantizer scale from the VPx lineage and use 0–63, where 0 is lossless and 63 is the worst quality. H.264 and H.265 use 0–51 (libx264/libx265 convention). They are not interchangeable: CRF 23 on AV1 is much higher quality than CRF 23 on x264. For web delivery, AV1 CRF 28–34 is typical; CRF 38–42 is "good enough for messaging."

My output is a .mp4 — is that still AV1?

Yes. AV1 is a video codec; MP4 (ISOBMFF) is a container. The Alliance for Open Media publishes the formal "AV1 Codec ISO Media File Format Binding" spec for storing AV1 inside MP4 boxes (AV1SampleEntry, AV1CodecConfigurationBox). MKV and WebM also carry AV1. To confirm the codec inside the container, run ffprobe yourfile.mp4 and check the video stream — it will say Video: av1.

Why does cutting AV1 feel slower than cutting H.264?

AV1 encoding is computationally far heavier than H.264 — typically 5–10× slower on libaom-av1 and 2–4× slower on SVT-AV1 at comparable presets. The decode side is fine (dav1d is fast), but every cut here re-encodes the kept segment, so a 30-second AV1 trim takes longer than the equivalent H.264 trim on the same hardware. Using Quality Preset "Medium" or "Low" speeds it up at the cost of bitrate efficiency.

Should I keep AV1, or convert to MP4/H.264 while I trim?

Depends on where the clip is going. AV1 wins for storage and bandwidth — same quality at ~30% smaller — but Safari < 17, older iOS, and most TVs/STBs older than ~2022 don't decode it. If you're posting to a Discord channel, sharing on Reels, or hosting on YouTube, keep AV1. If the recipient is on an older device or in a corporate environment, convert to MP4/H.264 in the same pass via AV1 to MP4. For long-term storage and broad playback, AV1 to MKV preserves AV1 in a container most desktop players handle.

Will the audio stay in sync after the cut?

Yes. The encoder re-muxes the audio Opus stream against the new video presentation timestamps, so audio drift is not an issue on well-formed AV1 sources. If your original was a screen capture with VFR (variable frame rate) timing — common for OBS — pick Quality Preset "High" or higher; aggressive bitrate caps can occasionally pull A/V out of alignment by a frame or two on VFR sources.

Can I cut and resize in the same step?

Yes — set Trim under Start Time/Duration, then change Video Resolution to a Preset (e.g. 720p) or a Resolution Percentage (e.g. 50%). Both happen in one FFmpeg pass. This is the cheapest way to produce a 1080p social cut from a 4K AV1 master without two round trips.

What's the difference between "Cut" and "Trim" here?

Mechanically nothing — both this page and Trim AV1 use the same Start Time / Duration controls and the same AV1 encoder. The two pages exist because users search both verbs; pick whichever wording matches what you'd type into a search box.

Why is my output bigger than I expected?

Two common causes. First, AV1 default CRF 30 produces a higher-bitrate stream than aggressive web presets — drop CRF to 34–38 if you want a smaller file. Second, if your source was a low-bitrate AV1 (say, a 2 Mbps YouTube download), re-encoding at default settings can actually increase size because the encoder produces a higher-quality output than the source. To shrink, use Compress AV1 with Target File Size %.