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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. This structure means trimming is not the simple operation it looks like: you can only cut cleanly at a keyframe, because cutting at a predicted frame would leave you with a frame that references data you just discarded. Most editors hide this by re-encoding the partial GOPs (groups of pictures) near the cut points, which is frame-accurate but slow. This trimmer gives you both options. Keyframe-accurate mode snaps your start and end points to the nearest I-frames, which lets the cut operate on the compressed stream directly, effectively a stream copy with just the cross-reference table rewritten. A 20-minute 4K video trims to an arbitrary segment in under a second with zero quality change, because no frames are ever decoded or re-encoded. Frame-accurate mode re-encodes the GOPs at each boundary to produce cuts at any frame position, which costs a few seconds of encode time but lets you trim to the exact frame rather than the nearest 2-10 second keyframe boundary.

Runs in your browser and files never uploadedMore 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. This structure means trimming is not the simple operation it looks like: you can only cut cleanly at a keyframe, because cutting at a predicted frame would leave you with a frame that references data you just discarded. Most editors hide this by re-encoding the partial GOPs (groups of pictures) near the cut points, which is frame-accurate but slow. This trimmer gives you both options. Keyframe-accurate mode snaps your start and end points to the nearest I-frames, which lets the cut operate on the compressed stream directly, effectively a stream copy with just the cross-reference table rewritten. A 20-minute 4K video trims to an arbitrary segment in under a second with zero quality change, because no frames are ever decoded or re-encoded. Frame-accurate mode re-encodes the GOPs at each boundary to produce cuts at any frame position, which costs a few seconds of encode time but lets you trim to the exact frame rather than the nearest 2-10 second keyframe boundary.

How to use

  1. 1Upload your video file by dragging it in or clicking the upload area.
  2. 2Scrub through the timeline and click "Set Start" at your desired beginning.
  3. 3Move to your end point and click "Set End" to define the clip range.
  4. 4Preview the selection, then click Export to download the trimmed video.

Key features

  • Frame-accurate trimming with visual timeline scrubber
  • Real-time preview of the selected segment
  • Waveform display for audio-guided editing
  • Keyboard shortcuts for precise navigation
  • Multiple export format options
  • Quality preservation with keyframe-aware cutting

Common use cases

  • 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.

How it works

The trimmer detects keyframe positions by parsing the video container (MP4, MOV, WebM) and extracting the sample-to-keyframe map. These positions are marked on the timeline as you scrub, so you can see at a glance which boundaries would produce a lossless stream-copy cut and which would require partial re-encoding. For most content, keyframes cluster around scene changes, so if you are cutting between natural visual beats (end of a sentence, cut to next shot) the keyframes are usually near enough that stream-copy mode lands close to where you wanted anyway.

For frame-accurate cuts, the trimmer decodes the partial GOP containing your cut point, encodes just those frames using the same codec and quality settings as the source, and concatenates the result with the unchanged stream-copied middle section. This produces output that is bit-identical to the original for 95%+ of its frames, with only the few frames at each boundary re-encoded. At typical web-video bitrates the difference is imperceptible, but it is there in principle, so if you are cutting pristine masters for further editing, keyframe-accurate mode is the safe default.

Audio handling is a separate concern. Audio samples are typically far smaller than video frames (a 44.1 kHz audio sample is a few bytes; a 1080p video frame is hundreds of kilobytes compressed), so audio granularity is essentially continuous compared to video keyframe spacing. The trimmer cuts audio at the exact sample position requested and the video at the nearest keyframe, which means in keyframe mode the output can have a few frames of video leading or trailing the intended cut while the audio is frame-accurate. For most content, podcasts, interviews, tutorials, this sub-10-frame offset is invisible. If you need strict A/V alignment at the sample level, use frame-accurate mode.

Frequently asked questions

Why does exporting sometimes take longer?

Frame-accurate cuts near non-keyframe positions require partial re-encoding, which takes more time than keyframe-based cuts. Higher resolution and longer clips also increase processing time.

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.

Private by design

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