Video Trimmer

How to Use the Online Video Trimmer

1. Drop or pick a video - MP4, WebM, MOV, MKV, AVI or any common container, up to 500 MB.
2. Set start and end times - drag the two slider handles, type MM:SS into the start/end fields, or pause the inline preview at a moment and click Use playhead to snap that timestamp into the field. The output length and total length update live.
3. Choose stream-copy or re-encode - leave it on stream-copy (default) for a fast, lossless cut. Tick "Re-encode" if you need a frame-accurate trim or a smaller file.
4. Click Trim video - the file is uploaded to our EU servers, ffmpeg runs the cut, and the result is returned to your browser. Cancel aborts the request at any time.
5. Preview and download - the trimmed clip plays inline. Save it as <original-name>-trimmed.<ext>.

What This Tool Does

This is a free video trimmer. It cuts a section out of a video file using server-side ffmpeg. The default mode is stream-copy: ffmpeg copies the original video and audio packets between the chosen start and end timestamps without re-encoding. That is fast - a 100 MB clip trims in seconds - and lossless because the source codec is preserved. The trade-off is that the cut snaps to the nearest keyframe before the start time, so a stream-copy trim is usually accurate to one or two seconds, not to the frame.

Why Trim Video Online

The point of an online video trimmer is to skip the desktop editor and avoid keeping a full editor installed for one short cut. The catch with most converters is unclear retention: a video uploaded to a third-party server might sit there indefinitely. Our trimmer solves that with a strict, automatic policy:

• Files are processed on EU servers and auto-deleted within 15 minutes of upload.
• The signed download link expires too - it is not a permanent public URL.
• Nothing is logged about the file content. Upload, trim, download, delete.

Stream-Copy vs Re-encode, Explained

• Stream-copy (-c copy) - the default. ffmpeg reads packets from the source and writes them straight to the output between your timestamps, with no decode-encode cycle. This is the fastest mode and produces a bit-for-bit copy of the original codec. Use it when you want to keep the original quality and you do not need to land on an exact frame.
• Re-encode (-c:v libx264 -crf 20 -c:a aac) - ffmpeg decodes every frame, re-encodes it with H.264 video and AAC audio, and writes a clean MP4. The cut is frame-accurate, the output is usually smaller than stream-copy, but the trim takes longer because it is a full transcode. Use it when you need a precise cut, when you want to compress the result, or when the source is a format your downstream tool cannot read.

How the Cut Works Under the Hood

For a stream-copy trim the api runs ffmpeg -ss <start> -to <end> -i input -c copy output. Placing -ss before -i tells ffmpeg to seek to the keyframe before the start timestamp very fast and then start copying packets.

For a re-encode the api keeps the same -ss/-to seek but switches to libx264 with a CRF of 20 and the fast preset, plus AAC audio at 192 kbps. CRF 20 is a strong general-purpose target that keeps file sizes modest while staying free of obvious compression artefacts.

Use Cases for the Free MP4 Trimmer

• Engineering teams - cut a 5-second bug repro out of a 5-minute screen recording before pasting the clip into a PR or ticket.
• Customer success and support - trim a Loom or Zoom export down to the relevant minute before sending it to a customer.
• Designers and product - clip a single interaction out of a long usability session for a Figma comment or a stand-up.
• Educators and trainers - extract a lecture excerpt for a Moodle or Canvas drop-in.
• Streamers and creators - cut a highlight from a long VOD for Twitter or Discord.
• Journalists and researchers - shorten an interview file before sharing the relevant segment with an editor or transcriber.

Tips for a Clean Trim

• If the result starts a beat early, increase the start time by 0.5-1 second. Stream-copy snaps to keyframes, so a small offset is normal.
• If the cut needs to be frame-accurate (for example, the first visible word of a sentence), tick the re-encode option. The trim takes longer but lands on the frame you asked for.
• For very long sources, trim the rough range first with stream-copy and then run a second pass with re-encode if you need to fine-tune the boundaries.
• Audio-only sources can also be cut with this tool by saving the result as the same audio extension. For dedicated audio editing, the audio trimmer is faster.
• If the output container is unusual, ffmpeg may complain about the codec-container combination. Switch to re-encode mode in that case - the resulting MP4 is the safest container.

Privacy and Browser Support

The tool works in any modern browser that can upload a file - recent Chrome, Edge, Firefox, Safari, and mobile equivalents. There are no SharedArrayBuffer or cross-origin-isolation requirements.

Files are uploaded over HTTPS to our EU-located servers, processed with ffmpeg, and made available via a signed, time-limited download URL. After 15 minutes the input and output are deleted from disk and the signed URL stops working. Nothing about your file content is logged or analyzed.