Media Tools · Video

Video Joiner_

Stitch several clips into one, drop on a logo, reframe to 9:16 or 16:9, and cover a watermark — all in your browser, with nothing uploaded. Powered by FFmpeg compiled to WebAssembly, so your footage never leaves your device.

Before you start: the first run downloads the ~30 MB video engine once (then it’s cached). Processing happens on your CPU, so it’s best for a handful of short clips rather than long files. Keep the total well under a few hundred MB.

1 Add your clips

⇧

Drop videos or click to choose

MP4 / MOV / WebM · added in order, reorderable below

2 Frame & fit

Aspect ratio

Scaling

3 Add a logo optional

Choose logo image (PNG with transparency works best)

4 Cover a watermark optional

Blur / cover a rectangular region

This blurs the chosen area (it can’t perfectly erase a logo). Please use it only on videos you own or have the rights to edit. The same region is covered on every clip.

How it works & the honest limits

Each clip is reframed to your chosen aspect ratio (cropping to fill, or padding with bars to fit), your logo is overlaid, and the optional cover region is blurred. The processed clips are then concatenated into a single MP4 — all locally, using FFmpeg.wasm.

It’s slow. Browser video encoding has no GPU acceleration and limited memory, so long or high-resolution files can take minutes or run out of memory. Trim clips first and keep the total modest. Output is 720p H.264 for broad compatibility.

About “removing” a watermark. No tool can cleanly erase a watermark baked into video; the realistic technique is to blur or cover the area, which is what this does. Use it only on footage you own or are licensed to edit — stripping someone else’s mark or attribution may infringe their rights.

Private by design. Built with AI assistance. Your videos never leave your device — all processing runs locally in your browser.