ENPTES

Merge videos into one file, on your device

Drop two or more clips, drag them into order, and download one MP4. FFmpeg runs in this browser, the same engine as the other video tools. The files are not uploaded.

Runs in your browser Free No sign-up
  1. Choose file
  2. Set options
  3. Get result

Your file never leaves your device. Processed locally in your browser. Nothing is uploaded.

How to merge videos

1. Drop the clips. 2. Drag the cards, or use the arrows, so the first clip is the one that should play first. 3. Leave Fast on when the clips came from the same camera. Choose re-encode when the sizes do not match. 4. Press “Merge videos” and download the MP4.

Fast copies the streams when the formats agree, so it finishes quickly. Re-encode makes one size and one frame rate. That takes longer because it uses one CPU thread.

Same engine as trim and compress

The converter is FFmpeg compiled to WebAssembly, loaded once from the CDN and then cached. It does not fetch video from a link. Leave the tab open until the download appears. A long re-encode can take about as long as the clips play.

What can go wrong

Clips with no picture are refused. If a clip has no soundtrack, the fast copy can fail and GustKit tries again without audio. Cut a clip with Trim video before you merge if you only want part of it. Nothing is stored after you close the tab.

How to keep the join in the right order

1. Drop the clips and drag the opening shot to the front before you press Merge. 2. Play the download for a second at each join, not only the start. 3. If the fast copy looks wrong, switch to re-encode and run again.

Fast is a copy, so a clip that starts between keyframes can freeze for a moment at the join. Re-encode avoids that and also fixes different sizes. Trim a clip first if you do not want the whole take.

Frequently asked questions

Do the clips have to be the same size?

No. Fast works when they already match. If the copy fails, or you pick re-encode, GustKit scales them into one 1280×720 frame with black bars when the shape differs.

Can I merge a video and an MP3?

Not on this page. This joins videos. Use the audio converter for sound, or Video to MP3 to pull a soundtrack out.

Why is the first run slow?

The FFmpeg engine downloads once. Later visits use the browser cache. Re-encode is slower than a copy even after that.

Are the videos uploaded?

No. Joining happens in this tab.

Can I add a title card between clips?

Not on this page. Merge only joins the videos you drop. Make the title as its own video, then drop it in the list.

The sound drops out after the first clip. What happened?

One of the later clips had no audio track, so the join continued without sound. Re-encode still needs an audio track on each clip to keep the soundtrack.