UseTool

100% LOCAL · LOSSLESS

Join videos. No quality loss.

Add videos, drag them into order and merge them locally in your browser.

Drop two or more videos hereorMP4, MOV, WebM, MKV and MPEG-TS — when the contained codecs can be copied safely
✓ This device is ready.The container and codecs inside each file are checked on this device after selection.

🔒 Your videos never leave your device.

Merge videos without uploading them

Add your clips, drag them into the right order and join them directly on your device. Matching clips are copied without re-encoding.

Automatic compatibility when clips differ

If H.264 profiles, resolutions or frame rates differ, UseTool can align them locally at high quality and then merge them. The tool clearly tells you when this one-time re-encoding is needed.

Works on phones and desktop browsers

The tool verifies the actual container and codecs on the current device. MP4, MOV, WebM, MKV and MPEG-TS are supported when their tracks can be copied safely. No video data is sent to a server.

How it works

How it works

  1. 1

    Add what goes in

    Drop at least 2 files here (MP4, M4V, MOV, WebM and 6 more formats) — the order you add them is the order they are used in.

  2. 2

    Start it

    Set the order of the clips, then start. Everything runs in this browser — no upload, no queue, no account.

  3. 3

    Take the result

    The WebM · MP4 is ready the moment the run finishes. Save it straight to your device.

What this tool does

Join Videos
Puts several clips one after another into a single file. Because the parts usually differ in resolution, frame rate or codec, they are brought to a common format — that is why this one re-encodes where the splitter does not.

When you need this

Supported formats

MP4, MOV, WebM, MKV and MPEG-TS — when the contained codecs can be copied safely

Good to know

Frequently asked questions

Which videos can be joined?

Clips that share the same codec and resolution are copied together untouched. When they differ, the parts that do not match are re-encoded so the result plays as one continuous video.

Does the order matter?

Yes, and you set it. Drag the cards or use the arrow buttons; the large number on each card is its position in the finished video.

What files can I use here?

Reads MP4, M4V, MOV, WebM and 6 more formats. At least 2 files at once.

What do I get back?

You get WebM · MP4.

Does the file lose quality?

Every frame is decoded and encoded again. That is what makes the file smaller or different — and it costs some detail, most visibly in fast motion and fine texture.

When does it not work?

Which video codecs work depends on your browser. Chrome and Edge read the most, including H.265 on many machines; Safari and Firefox refuse some. A file that will not open here usually opens in Chrome. A long or high-resolution video is limited by your device's memory. Phones give up earlier than laptops — half an hour of 4K can be too much.

Does the video lose quality?

Only when it has to be re-encoded. Cutting, joining and removing the sound track copy the picture data unchanged, so those are lossless. Compressing and adding a watermark do re-encode, which is why they take longer.

How long may a video be?

There is no fixed limit. What decides is the memory of your device: a phone manages a few minutes comfortably, a computer handles far more. If a long video fails, splitting it first and working on the parts usually helps.

Private by design

Your files stay on your device

Your videos never leave your device.

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