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  1. Home
  2. Video Processing
  3. Video Trimmer - Cut & Clip Videos Online
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Video Trimmer - Cut & Clip Videos Online

Trim and cut videos precisely with frame-by-frame scrubbing. Set start/end points visually, preview clips in real-time, and export trimmed videos instantly. No upload required - runs 100% in browser.

Modern video compression does not store every frame independently; it stores keyframes (I-frames) that contain complete image data and predicted frames (P-frames and B-frames) that describe changes from neighboring frames. A typical H.264 clip has keyframes every 2-10 seconds. That structure is why a naive cut at an arbitrary point can break: if you start a clip on a predicted frame, that frame references data the cut just discarded, so the opening looks corrupted until the next keyframe arrives. This trimmer avoids that problem by re-encoding the trimmed range rather than copying compressed packets. You set a start and end point on the timeline and the tool decodes from your exact start position and writes a fresh H.264 video stream plus an AAC audio track, so the cut lands on the precise frame you chose regardless of where the source keyframes fall. The trade-off is that trimming is an encode rather than an instant stream copy, so a long or high-resolution clip takes processing time proportional to its length. In exchange you get frame-accurate in and out points and a clean first frame every time, with no keyframe snapping or dependence on where the original encoder happened to place its I-frames.

Video stays on your deviceMore video processingJump to full guide

Related reading

  • Creating GIFs from Videos: Techniques and Best Practices13 min read
  • Video Editing in the Browser: Trim, Merge, Convert, and More14 min read

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Video Trimmer - Cut & Clip Videos Online: a worked example

A 4-minute screen recording has only a 20-second section worth keeping for the bug report.

Input

screen.mp4 · keep 01:12 → 01:32
Video Trimmer - Cut & Clip Videos Online produces

Output

clip.mp4, 20 s, trimmed without re-encoding where possible

Cutting on keyframes lets the tool trim without a full re-encode, so quality is untouched and the export is near-instant. Everything runs in the browser via WebAssembly, the recording is never uploaded.

What is Video Trimmer - Cut & Clip Videos Online?

Modern video compression does not store every frame independently; it stores keyframes (I-frames) that contain complete image data and predicted frames (P-frames and B-frames) that describe changes from neighboring frames. A typical H.264 clip has keyframes every 2-10 seconds. That structure is why a naive cut at an arbitrary point can break: if you start a clip on a predicted frame, that frame references data the cut just discarded, so the opening looks corrupted until the next keyframe arrives. This trimmer avoids that problem by re-encoding the trimmed range rather than copying compressed packets. You set a start and end point on the timeline and the tool decodes from your exact start position and writes a fresh H.264 video stream plus an AAC audio track, so the cut lands on the precise frame you chose regardless of where the source keyframes fall. The trade-off is that trimming is an encode rather than an instant stream copy, so a long or high-resolution clip takes processing time proportional to its length. In exchange you get frame-accurate in and out points and a clean first frame every time, with no keyframe snapping or dependence on where the original encoder happened to place its I-frames.

How to use

  1. 1Upload your video file by dragging it in or clicking the upload area.
  2. 2Scrub the timeline (or use the arrow keys) and press I to set the start point.
  3. 3Move to your end point and press O to set the end of the clip range.
  4. 4Preview the selected range, then click Export to download the trimmed video.

When to use it

  • Social media clips

    Extract the best moments from longer recordings to create short, engaging content for TikTok, Instagram Reels, or YouTube Shorts.

  • Cleaning up screen recordings

    Remove setup time, menu navigation, and dead air from screen captures to deliver concise tutorials.

  • Presentation excerpts

    Pull relevant video clips from recorded meetings, webinars, or lectures for use in slide decks and reports.

  • Highlight reels

    Cut standout plays, performances, or moments from long event recordings into shareable highlights.

Key features

  • Frame-accurate in/out points with a visual timeline scrubber
  • Real-time preview of the selected segment
  • Keyboard shortcuts: Space play/pause, I/O set start/end, arrows seek, M mute, F fullscreen
  • Runs fully in-browser via FFmpeg WebAssembly, files never uploaded
  • Re-encodes to H.264 video and AAC audio at near-transparent CRF 23 quality
  • Output keeps the original container (MP4 stays MP4, WebM stays WebM)

How it works

Everything runs in the browser through FFmpeg compiled to WebAssembly, so the file never leaves your device. When you export, the trimmer seeks to your chosen start time by placing the seek after the input (decode-then-seek), which is slower than seeking before the input but accurate to the frame, then encodes the selected duration with libx264 at the ultrafast preset and CRF 23 and re-encodes audio to AAC. Because the whole range is re-encoded rather than copied, the output is not bit-identical to the source: it is a fresh encode at visually-high quality (CRF 23 is widely treated as near-transparent for web video), which is the right default for sharing and posting. If you are cutting a pristine master for further editing where you need the original packets untouched, this browser trimmer is not the tool for that, a packet-copy editor is.

The output keeps the same container as your upload (an MP4 stays an MP4, a WebM stays a WebM); there is no separate output-format chooser, so to change container or codec you would convert the trimmed clip afterward with the format converter. The timeline gives you a scrubber, start and end markers, a live preview of the selected range, and a running readout of the trim duration and how much you are removing.

The editor is built for keyboard-driven precision: Space toggles play/pause, I sets the start point at the playhead, O sets the end point, the left and right arrows seek, M mutes, and F toggles fullscreen. That lets you nudge the playhead frame by frame and mark in/out points without leaving the keyboard, which is far faster than dragging handles when you are hunting for an exact cut.

Frequently asked questions

Why does exporting take some time?

The trimmer re-encodes the selected range with H.264 rather than doing an instant stream copy, which is what makes the cut frame-accurate. Processing time grows with clip length and resolution, so a long or high-resolution selection takes longer than a short one.

Is there a file size limit?

There is no hard limit, but very large files (over 2 GB) may be slow to load depending on your device's available memory.

Can I trim multiple segments at once?

The tool currently supports a single trim range per export. To extract multiple segments, export one clip and then reload the video for the next.

Further reading

  • Creating GIFs from Videos: Techniques and Best Practices13 min read
  • Video Editing in the Browser: Trim, Merge, Convert, and More14 min read

Private by design

Video is decoded and re-encoded on your own device. Large files never leave your machine.