Merge Videos Online

Add at least two clips, put them in order, choose the output format, merge, then download one combined file.

1. 1

   Add your clips

   Drop in two or more MP4, MOV, WebM or MKV files, or click to browse.

2. 2

   Put them in order

   Move clips up and down until the running order is right. Trim any clip that needs it.

3. 3

   Choose the output

   Pick MP4, WebM, MOV or MKV, and decide how clips of different shapes should be handled.

4. 4

   Merge

   Press Merge. Matching clips are joined without re-encoding; anything else is re-encoded to one consistent video.

5. 5

   Download

   Play the result to check it, then save the combined file.

Merging turns several clips into one continuous file — a compilation from a day's filming, a lesson recorded in parts, a screen recording that stopped and started, or simply one file to send instead of nine.

Join clips end to end — without re-encoding when they already match.

What you get from merging here

• One file: Share or upload a single video instead of a folder of clips.
• Order you control: Move clips up and down, or jump one straight to a position, before you export.
• No quality lost, when it can be avoided: Clips that already match are joined by copying their existing video data rather than re-encoding it.
• Shapes handled properly: A portrait clip next to a landscape one is fitted inside the frame, not squashed to fit it.
• Nothing uploaded: The clips are read on your device and never leave it.

Most online video mergers re-encode everything, because they run on a server and have no other option. That costs a generation of quality on every join, and it is why merged files so often come back larger and softer than the clips that went into them. This tool checks first, and when the clips already agree it copies their existing video data straight into the new file — the picture that comes out is the picture that went in.

When clips are joined without re-encoding

• Every clip uses the same video format and the same frame size.
• Every clip has audio in the same format, or no clip has audio at all.
• You have not chosen a transition, a different resolution or a different frame rate.
• The output container can carry that video format — MKV can carry anything, which is why it is offered.

When a re-encode is needed instead

• The clips are different sizes or shapes, so they have to be drawn into one common frame.
• The clips came from different sources and use different video formats.
• Some clips have sound and others do not, so silence has to be created for the quiet ones.
• You asked for a crossfade, a specific resolution or a specific frame rate.

The tool tells you which of the two it is about to do, before you press Merge, and confirms which one it did afterwards.

A music bed plays under the whole finished video, mixed with whatever sound the clips already have. Adding one does not cost you the picture: when the clips match, the video is still joined by copying it and only the audio is rebuilt — so a soundtrack no longer means re-encoding every frame.

What you control

• Level — how loud the music sits under the clips.
• Clip audio — how far the clips' own sound is pushed down while the music plays, for a talking-head video that needs the bed underneath rather than over the top.
• Repeat or play once — a short loop fills a long video, or a piece with a real ending stops where it ends.
• Fade in and fade out — both capped at half the finished video, so two fades can never overlap.

Worth knowing

• The music is always cut off at the end of the video. A video that kept running on a black frame to finish the song would be a worse answer than a fade.
• A clip with no sound of its own still gets the bed — silence is created for it so the music keeps playing.
• Music takes MP3, M4A, WAV, OGG, FLAC and AAC. Each was checked by opening a real file, not by trusting an extension.

Merging is not the same as editing. There is no timeline with overlapping layers here — clips are placed end to end, in the order you set, and written into a single container. What varies is how much work that takes.

The merge, step by step

• Read: Each clip's header is read to find its size, length, frame rate and formats. Nothing is decoded yet.
• Compare: The clips are checked against each other to decide whether they can be joined as they are.
• Join or rebuild: Matching clips are copied through; mismatched ones are decoded, fitted into a common frame and re-encoded.
• Write: Video and audio are written into one MP4, WebM, MOV or MKV file.
• Download: You play it back and save it.

A file's extension tells you very little about whether it can be opened — an MP4 can hold any of half a dozen different video formats, and which of them your browser can read depends on your device. So the supported list here is a closed one, checked when you pick a file rather than after you have waited for it.

What you can put in

• MP4 — the common case, from phones, cameras and most editors.
• MOV — QuickTime, which is what iPhones and Macs record.
• WebM — usually from screen recorders and online recording tools.
• MKV — a container that can hold almost anything, common for longer recordings.

What you can get out

• MP4 — the safest choice, playable essentially everywhere.
• MOV — for Apple-centric workflows and Final Cut.
• WebM — for the web, where a smaller file matters more than universal support.
• MKV — the only one that can carry every combination, so it is the one that always allows a join without re-encoding.

What is refused, and why

• AVI, WMV, FLV, MPEG, OGV and 3GP are refused when you pick them, with the format named.
• These are older containers whose video formats no browser can decode, so no online tool of this kind can open them on your device — trying another browser will not help.
• The refusal happens immediately and points you at a converter, rather than starting work that cannot finish.

A few facts that explain most of the surprises people run into when joining clips.

Key points

• When clips are joined without re-encoding, the merged file is very close to the sum of the inputs — not larger.
• When a re-encode is needed, the quality setting decides the size, and it is capped by what the source clips actually contain: re-encoding cannot add detail that was never recorded.
• Choosing a resolution sets a ceiling, not a target. Four 720p clips exported at the 1080p setting stay 720p, because enlarging them would cost bytes and add nothing.
• 'Match first clip' uses the first clip's real frame rate, whatever it is — a 10 fps screen recording stays at 10 fps.
• A crossfade overlaps two clips, so it makes the finished video shorter than the sum of its parts, not longer.
• If one clip has no sound, silence is created for it so the audio runs the whole length instead of stopping part-way.

How to get a clean result with the fewest surprises.

Getting the best quality

• Clips from the same camera, phone or screen recorder almost always join without re-encoding — that is the best possible result, and it is free.
• If you are going to trim clips anyway, do it here rather than exporting from an editor first; every extra export costs a generation.
• Choose MKV if you want to guarantee no re-encode and do not need the file to play in a browser.
• Choose MP4 if the file has to play anywhere at all — it is worth a re-encode for that if your clips are mixed.
• Use High quality when the clips do have to be re-encoded, particularly for footage with a lot of movement.
• Play the merged file through before deleting your originals.

Common use cases

• Compilations: Build a highlight reel from a day's worth of short clips.
• Lessons and tutorials: Join parts recorded in separate sittings into one continuous lesson.
• Meetings and calls: Combine a recording that split into several files for archiving.
• Phone footage: Join clips that stopped at the recording limit back into one video.
• Creators: Bundle takes into one file before handing it to an editor or a client.

Every clip is read on your device. The container is parsed to find the tracks inside it, and your browser's own media engine is asked whether it can decode them — a question about headers, not pixels, which is why an unopenable file is refused in a fraction of a second rather than after a wait.

What happens to your clips

• Inspect: Each clip's tracks, dimensions, frame rate, timing and data rate are read from its header.
• Decide: The clips are compared. If they agree on everything that matters, the compressed video data can be reused as it is.
• Copy or rebuild: Matching clips have their existing video data written straight into the new file. Mismatched clips are decoded, drawn into a common frame and encoded once.
• Re-time: Each clip's timing is shifted onto the finished video's timeline, so the clips run continuously with no gap between them.
• Write: Video and audio are written into the container you chose, and handed to you as a file.

Joining is handled by our own on-device pipeline, hardware accelerated where your device supports it.

• Video compressor
• Video resizer
• Video cropper
• Video cutter
• Replace audio
• Extract audio