Can I merge videos with different sizes or orientations?

Yes. Clips that differ in size, shape or frame rate are scaled to fit one frame — the first clip's size, 1080p or 720p — with black bars where needed. Nothing is cropped or stretched.

Does merging reduce video quality?

Not when the clips match. If every clip has the same codec, frame size, frame rate and audio format — typical for clips from one phone — they are joined without re-encoding. Mixed clips are re-encoded once to H.264 MP4.

Are my videos uploaded?

No. The FFmpeg engine runs inside your browser and reads the clips from your device; the merged MP4 is built in memory and never sent to a server. Very large merges may not fit in a phone's memory.

Is this Video Merger really free?

Yes, completely free. No limits, no login, no credit card — ever.

Is there a file size limit?

No file size limits. The only constraint is your browser's available memory.

Does it work on mobile?

Yes — fully tested on iOS and Android in all modern browsers.

Do you store my files?

Never. We cannot see your files. They stay on your device the entire time.

🎞️

Free Video Merger

Merge several video clips into one MP4 in the order you choose. Different sizes are fitted with black bars; matching clips join without re-encoding. Runs in your browser — no upload.

No forced size limitFiles stay privateNo login requiredFree foreverNo daily limitNo watermark

Drop files here, or click to browse

MP4, WebM, MOV, AVI, MKV, M4V · no forced size cap

or press Ctrl+V to paste from your clipboard

You can drop multiple files at once

Browse files

Your files never leave your device. All processing happens locally in your browser.

How It Works

Joins several video clips into one MP4, in the order you choose, with the FFmpeg engine running in your browser. Clips of different sizes or shapes are fitted into one frame with black bars instead of being stretched or cropped.

1
Add and order your clips
Drop in MP4, MOV, WebM or MKV files, then drag them or use the up/down arrows to set the order. Tap a thumbnail to preview a clip.
2
Each clip is checked
FFmpeg (WebAssembly, ~31 MB, downloaded once and cached) reads every clip's codec, frame size, frame rate and audio format. Nothing is uploaded.
3
Matching clips are joined as-is
When every clip shares the same codec, size, frame rate and audio (e.g. several clips from one phone), they are joined by stream copy with FFmpeg's concat demuxer — no re-encoding and no quality loss.
4
Mixed clips are re-encoded to one frame
Otherwise each clip is scaled to fit the output size (same as the first clip, 1080p or 720p), padded with black bars, set to one frame rate and encoded to H.264 with AAC audio. Clips without sound get silence so the audio stays in sync.