Free tool · runs in your browser

Video Merger

Combine two or more clips into a single MP4. When the inputs match, they're stream-copied (fast, lossless); when they differ in resolution or codec the tool warns you and re-encodes to a common format so the joins are seamless. Drag to reorder, no upload, no account.

How to use this tool

  1. 01

    Add your video files

    Drag and drop them in the order they'll play, or click to add — MP4, MOV, MKV, WebM.

  2. 02

    Reorder if needed

    Drag rows (or use the up/down controls) to fix the sequence before merging.

  3. 03

    Merge

    The tool auto-detects whether a stream copy is possible (fast) or re-encoding is needed (slower).

  4. 04

    Download the merged file

    Preview the joins in the player and verify playback before deleting your source files.

Why this matters

Building a supercut or stitching recorded segments together shouldn't require uploading gigabytes to a server or learning the FFmpeg concat syntax. The hard part is that the fast stream-copy join silently breaks when clips disagree — which is the common case for user footage from different devices.

This tool probes every clip, takes the instant stream-copy path when they match, and automatically re-encodes (with a clear warning) when they don't, so the output always plays. To make a mismatched set uniform up front and keep the fast path, run the clips through the Video Format Converter first.

Related tools

FAQ

Almost always because the input clips disagree — different codecs, framerates, resolutions, or audio sample rates. A naive stream-copy join of mismatched files produces audio drift, frozen video, or a file that won't play. This tool detects the mismatch, warns you, and re-encodes to a common format instead; if you'd rather keep the fast path, make the clips uniform first in the Video Format Converter.

Explore the full toolkit

94 free tools covering titles, tags, thumbnails, scripts, captions, embeds, schema, and in-browser video processing.

Browse all tools →