Video Trimmer

How to use the video trimmer

Upload a video file by dragging it into the upload zone or clicking to browse. Use the dual-handle slider to set the start and end points of your trim, or type the exact times in the fields below. Click “Set start” and “Set end” while the video is playing to mark trim points from the preview. For a single clip, select your output format and click Trim and export. For multiple clips from the same video, switch to multi-clip mode and add as many clip ranges as needed — each can have a different format. All clips are processed and downloaded separately.

How video trimming works in your browser

This tool uses FFmpeg compiled to WebAssembly — the same FFmpeg engine used in professional video editing software, running entirely within your browser tab. Your video file is never transmitted to any server. On first use, the browser downloads the FFmpeg WebAssembly engine (approximately 30 MB), which is then cached locally for instant use on subsequent visits. The trimming process re-encodes the selected clip using the libx264 codec for MP4 output, which ensures clean cut points regardless of where the original keyframes were. Stream copy (faster but less accurate) is not used because it can produce clips that start on a non-keyframe and show a black or partial frame at the beginning.

Choosing the right output format

MP4 (H.264) is the safest choice for sharing — it plays in every browser, phone, social media platform, and messaging app without any compatibility issues. WebM (VP9) produces smaller files and is well-supported in modern browsers but may not play in older applications or on some devices without additional codecs. MP3 is the correct choice when you only need the audio track — for extracting a podcast segment, a song, or dialogue from a video. WAV produces an uncompressed audio file that is much larger than MP3 but with no quality loss, which makes it appropriate for audio editing workflows where re-encoding is planned.

Tips for accurate trimming

For precise trim points, play the video and press I on your keyboard to mark the start of the clip and O to mark the end at the exact moment you want. The slider provides coarse selection while the keyboard shortcuts allow frame-accurate marking during playback. The time input fields accept seconds (83.5), MM:SS format (1:23), or HH:MM:SS format (0:01:23) — enter the exact time if you know it. Processing time depends on clip length, output format, and your device’s processor speed — a 30-second MP4 clip typically takes 5–15 seconds to process on a modern device.

Frequently Asked Questions