VIDEO MERGER
Combine multiple videos into a single MP4 — entirely in your browser. No upload, no account.
Drop your video files here
or click to select files
Up to 5 videos · Max 200 MB each · Files never leave your device
How Video Merging Works in Your Browser
AI Toolbox uses FFmpeg.wasm — a WebAssembly port of FFmpeg — to combine your videos entirely within your browser. Files are never sent to a server.
How to Merge Video Files
Upload your videos
Drop up to 5 video files (MP4, MOV, MKV, WebM, AVI and more) into the upload area or click to select them.
Reorder if needed
Drag the files into your desired order. The merged MP4 will follow this sequence.
Merge and download
Click Merge Videos and download a single combined MP4 — entirely from your browser.
Why Use AI Toolbox Video Merger?
100% Private
Your videos never leave your device. All merging happens locally in your browser using FFmpeg.wasm — no server, no cloud, no third-party access.
Drag-to-Reorder
Arrange your clips in any order before merging. Drag and drop to reorder, or use the up/down arrows on touch devices.
Universal MP4 Output
Output is H.264 + AAC inside MP4 — playable on every modern device and browser without extra software.
Smart Compatibility
Mismatched codecs or resolutions? The tool re-encodes everything to a uniform MP4 so the result always plays.
Supported Input Formats
MP4, MOV, MKV, WebM, AVI, WMV, FLV, 3GP, MPG, OGV. The output is always MP4 (H.264 video + AAC audio) at 1280×720 for maximum compatibility.
How AI Toolbox Compares
See how browser-based video merging compares to typical online tools.
| AI Toolbox | Clideo | Kapwing | Online-Convert | Adobe Express | Veed.io | |
|---|---|---|---|---|---|---|
| Speed | Fast (local) | Upload required | Upload required | Upload required | Upload required | Upload required |
| Privacy (no upload) | ||||||
| No watermark | ||||||
| No account required | ||||||
| Works offline | ||||||
| Free |
AI Toolbox
Clideo
Kapwing
Online-Convert
Adobe Express
Veed.io
Frequently Asked Questions
Is this video merger really free?↓
Yes, completely free with no hidden costs, watermarks, or signup required.
Are my videos uploaded to a server?↓
No. All merging happens locally in your browser using FFmpeg.wasm. Your files never leave your device.
How many videos can I merge at once?↓
Up to 5 video files per merge, with a 200 MB limit per file. Run the tool again to combine more.
Which input formats are supported?↓
MP4, MOV, MKV, WebM, AVI, WMV, FLV, 3GP, MPG, and OGV. The output is always MP4 (H.264 + AAC) for maximum compatibility.
What if my videos have different resolutions or codecs?↓
The tool detects mismatches and automatically re-encodes everything to a uniform MP4 (1280×720). This takes longer but guarantees a playable result.
Why is the output MP4 and not my original format?↓
MP4 (H.264 + AAC) plays on virtually every device and browser. Combining clips from different sources reliably requires a single, well-supported output container.
Can I merge very large videos?↓
Each file is capped at 200 MB to keep processing reliable in the browser. Larger merges may run out of memory depending on your device.
Does this work on mobile?↓
Yes. The tool is fully responsive. Note that FFmpeg.wasm uses meaningful CPU and memory — desktop browsers handle large merges more comfortably.
Ready to merge your videos?
Drop your files above and get a single MP4 in seconds — no account, no upload.
Merge Videos FreePrivacy & Security
AI Toolbox Video Merger runs entirely in your browser. No video data is transmitted to any server. Processing uses FFmpeg.wasm. Files are read from your local device and the merged result is downloaded directly to your device.