NoCloud Media

Video tool

Video Joiner — Combine Clips

Stitch MP4, MOV, WebM, MKV, AVI clips into one MP4. Runs entirely in your browser.

How it works

  1. 1

    Drop two or more video clips

    Mix and match formats — MP4, MOV, WebM, MKV, AVI, or M4V.

  2. 2

    Put them in order

    Clips join end-to-end in the order shown. Reorder with the up/down buttons before joining.

  3. 3

    Join in your browser

    Each clip is normalized to 720p/30fps/stereo before the concat filter runs, then the result re-encodes as MP4 (H.264 + AAC).

  4. 4

    Download the combined video

    Single MP4, ready to share or upload anywhere.

Why use Video joiner?

Handles format mismatches — inputs can be different codecs, containers, or framerates. The concat filter normalizes them.

Private — your clips never leave your browser.

Predictable — clips join strictly in the order you pick, no cross-fades, no fade-to-black guesses.

Common use cases

  • Stitch a gameplay montage from several highlight clips
  • Combine camera rolls from a multi-day shoot into one file
  • Merge a title card, main clip, and end card into one video
  • Glue a series of phone videos into one shareable MP4
  • Concatenate tutorial segments recorded in separate takes
  • Produce a compilation reel from individual scenes

About MP4 and MP4

Joining videos requires every input to share resolution, framerate, pixel format, and audio format. Rather than fail on mismatches, NoCloud Media normalizes each clip to 1280×720 at 30 fps (with black letterboxing for non-16:9 sources) and 44.1 kHz stereo audio before running FFmpeg's `concat` filter. The output is MP4 (H.264 video at CRF 23, AAC 128 kbps audio). Because the filter re-encodes, this is the slowest of the video tools — expect a few minutes for several HD clips on a laptop, longer on mobile.

Frequently asked questions

Is my video uploaded to a server?
No. NoCloud Media joins your clips entirely in your browser using WebAssembly. Your files never leave this tab.
Can I mix different formats and resolutions?
Yes. Every input is normalized to 1280×720 at 30 fps before the concat — non-16:9 clips get black letterboxing to fit, and framerates are resampled. That keeps the filter happy regardless of input variance. Output resolution is fixed at 720p in this version; a resolution picker may come later.
Can I add crossfades or transitions?
Not in this tool. NoCloud Media joins clips end-to-end with no overlap. For transitions, a dedicated editor (DaVinci Resolve, Final Cut, CapCut) is the right tool.
What if one of my clips has no audio?
The concat filter requires every input to have both a video and an audio stream. If one clip is silent, mute all of them first (via the mute-video tool) so they have a matching structure, or add a silent audio track in a dedicated editor.
What's the maximum combined size?
It depends on your browser's available memory. As a rule of thumb, keep the combined input size under 1GB for smooth processing on most devices.
Which browsers are supported?
Chrome, Edge, Firefox, and Safari 15+. We require WebAssembly and SharedArrayBuffer, both standard in modern browsers.

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