Question 1

How do I merge multiple videos into one?

Accepted Answer

Upload 2 or more video files by dragging them into the upload area or clicking to browse. Reorder them with the up/down buttons if needed. Click Merge Video — the tool will stitch them into a single file using your browser's video decoder. No upload, no server.

Question 2

What video formats are supported?

Accepted Answer

Any format your browser can play — typically MP4 (H.264/AAC), WebM (VP9/Opus), MOV (often MP4-based) and M4V. The merged output is WebM (VP9 + Opus), which plays in every modern browser and is supported by most video editors.

Question 3

Is there a file size or duration limit?

Accepted Answer

No hard limit, but very large or long videos use a lot of memory. For best results, keep individual clips under ~5 minutes and total duration under ~30 minutes. All processing is local — your videos never leave your device.

Question 4

Does my video get uploaded anywhere?

Accepted Answer

No. Decoding, processing and encoding all run locally in your browser using HTMLVideoElement, Canvas and MediaRecorder. Nothing is sent to any server. Close the tab and your files are gone.

Question 5

Will the merged video keep audio?

Accepted Answer

Yes. The tool captures the audio track using Web Audio and mixes it with the video frames. Final output has both video (VP9) and audio (Opus) tracks in the WebM container.