Cutting a video in After Effects means selecting a portion of a clip between two timecodes and exporting just that range. After Effects supports this through its layer trimming controls and work-area previews, but the workflow requires the full Creative Cloud installation, a project setup, and a render queue to produce the final file. For a fast start-and-end cut from a local MP4, MOV, WebM, M4V, or Ogg file, Video Trimmer performs the same bounded selection directly in the browser. You pick the file, wait for its duration to load, type two numbers in seconds, and download a new WebM that contains only the chosen range. The source video is decoded, seeked, and re-encoded inside the current browser tab, so the original file is never uploaded to a server. The output's length is written into the container's Segment Info, which makes compatible players report a finite timeline for the trimmed clip rather than streaming the full original.
Why People Land on After Effects for a Simple Cut
After Effects is a motion graphics and compositing tool, but it is also widely known by name, which is why a search for "how to cut video in After Effects" is so common. The actual capability most searchers want is a clean cut between two times. After Effects can deliver that through layer in and out points, the work area, and previews. The trade-off is overhead: a project file, a composition, render settings, and a render queue. For a single bounded clip from a local file, this is heavier than the task requires, especially when the source never needs motion graphics or compositing.
A browser-based trimmer offers a different path. The work is two timecodes and a button. There is no project file, no render queue, and no need to keep a Creative Cloud subscription active just to slice one clip into a new file. The trade is that the result is a WebM re-encode rather than an After Effects render, but for a quick shareable segment that is usually the desired outcome.
How Video Trimmer Handles a Local File
Video Trimmer reads a local video in MP4, WebM, MOV, M4V, or Ogg container up to 500 MiB and exposes its decoded duration. You then enter two numbers in moments that describe the start and end of the clip you want to keep. The tool seeks the media element to the start time, captures the browser-exposed media stream, and records until the requested end time. The result is a WebM file whose length matches the chosen range.
Every step, including decode, seek, capture, record, and write, runs in the current browser tab. The original file stays on your device and is not uploaded. The final WebM is offered as a download through a revocable Object URL. Under the hood, the tool uses the browser's built-in MediaRecorder interface to re-encode the captured stream into a WebM container, which is why it does not need a heavy media library or server-side processing. The MediaRecorder approach is documented in the MDN Recording a media element guide, which describes the same seek-then-capture pattern this tool follows.
Cut a Video by Start and End Time
- Open Video Trimmer and choose one supported local video. Wait for the duration field to populate, which confirms the browser can decode the file.
- Enter the start time almost instantly. The value can include milliseconds and must be zero or greater.
- Enter the end time almost instantly. It must be later than the start and no later than the decoded duration.
- Confirm the selected range is at least 0.1 seconds. Smaller ranges fail visibly rather than being clamped.
- Select Trim video. The interface reports the requested duration and output size.
- Download the resulting WebM file. The selected duration is written into the container's Segment Info so compatible players show a finite timeline.
For example, if the source duration is 240 seconds and you want to keep the segment from 12.5 to 47.25 seconds, type 12.5 as the start and 47.25 as the end. The trimmed clip's duration would be 47.25 − 12.5 = 34.75 seconds. The interface will show 34.75 seconds as the reported duration when you confirm the trim.
Input and Output Limits to Watch
Video Trimmer accepts only what the browser can actually decode. A familiar extension does not guarantee success because the current browser must also decode the codecs inside the container. If a file fails, the usual cause is a codec the current browser cannot read, not the filename.
| Constraint | Limit |
|---|---|
| Supported containers | MP4, WebM, MOV, M4V, Ogg |
| Maximum file size | 500 MiB |
| Maximum decoded duration | 5 minutes |
| Maximum width or height | 4096 pixels |
| Maximum total area | 3840 × 2160 pixels |
| Minimum selected clip | 0.1 seconds |
| Start value | 0 seconds or greater, decimal allowed |
| End value | Greater than start, no later than decoded duration |
Reversed or out-of-range inputs fail visibly rather than being corrected automatically, so the user always sees why a request was rejected instead of guessing what was meant.
What the Output Preserves and Re-Encodes
The output is always WebM, using a codec selected from the browser's supported VP9, VP8, and optional Opus combinations. Dimensions are preserved. Quality, keyframes, color metadata, audio layout, and file size can all differ from the source because the trim is a real-time re-encode, not a packet-level lossless cut. The WebM Segment Info receives the selected duration so compatible players report a finite timeline for the new file.
The last encoded frame can land a small fraction around the requested boundary, because MediaRecorder samples playback time and does not expose frame-accurate editing. If playback reaches the end time slightly after the requested frame, the clip may include a few extra milliseconds; if it reaches slightly before, the clip may end a hair short. This is usually invisible in normal viewing but matters when the cut must align to a specific frame.
For broadcast delivery, exact keyframe cuts, subtitle preservation, multitrack audio, long footage, or a required MP4 codec, use a dedicated desktop editor and inspect the exported timeline. Video Trimmer is designed for convenient local trimming, not professional frame accuracy. It does not bypass DRM, fetch remote media, or remove watermarks, and the license expectation is the same as any editor: use it only on video you own or have permission to edit.
When Video Trimmer Is the Right Fit
Use Video Trimmer when the task is exactly what its three steps describe: pick a local file, enter a start and end, download the resulting WebM. It fits social clips, internal review cuts, trimming a recorded screen capture to the relevant seconds, or extracting a segment from a downloaded source for messaging or email. Because the source never leaves the browser tab, it also fits workflows where privacy or limited bandwidth makes uploading a video impractical.
For other tasks, the Video Cropper adjusts the visible frame to a pixel rectangle, the Video Compressor re-encodes for a target size, and the Video to Audio Converter extracts only the audio track. Each of those runs on the same local-only principle, so the source file still never leaves the browser tab during processing.