How to stitch 4k clips together with no quality loss
- Step 1Drop your clips in order — Add your clips in playback order
- Step 2Choose lossless or transcode mode — JAD picks stream-copy if codecs match, re-encode otherwise
- Step 3Download the merged video — Download the merged video
Frequently asked questions
When does lossless merge work and when does it transcode?+
Lossless stream-copy works when all clips share the same codec, resolution, frame rate, and audio format. If any of these differ between clips — e.g. mixing 1080p and 4K, or H.264 and H.265 — JAD automatically switches to transcode mode to produce a consistent output. You can force transcode mode even for compatible inputs if you prefer to standardise the output specification.
Why is there a slight stutter at the join point in my merged video?+
Stutters at join points usually occur when the clips have different keyframe intervals or frame rates. In stream-copy mode, the concat demuxer preserves each clip's timing as-is, which can create a brief non-smooth transition. Transcoding mode re-encodes all clips to a uniform spec and eliminates these artefacts at the cost of processing time.
Can I reorder clips before merging?+
Yes — drag clips into the desired order in the drop zone before running the merge. The concat demuxer processes them in the order they appear in the file list, so the output matches exactly what you arranged.
Privacy first
All video processing runs locally in your browser using WebAssembly and FFmpeg. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.