Clip Joiner

Install Clip Joiner

Clip Joiner runs on macOS 14 Sonoma or later, on Apple silicon and Intel Macs. After buying, download the app zip from your Polar receipt, unzip it, and drag Clip Joiner to your Applications folder.

The app is signed and notarized by Apple. Confirm Open at the normal first-launch prompt.

The app works without a license key. The key in your receipt turns on automatic updates: enter it in Clip Joiner → License…. Once a day, Clip Joiner checks for a new version, shows what’s new, and installs it with Install and Relaunch. A key works on 3 Macs. Your receipt always has the latest version, too.

Scan a card or a folder

The start screen offers a few ways to find your videos.

Plug in a memory card and the start screen gets a button with the card’s name, like Scan NO NAME. Click it and the app looks for videos on the card.

For videos already on your Mac:

• Drop a card, a folder or video files on the window.
• Click Choose Folder… and pick a card, a folder or the video files themselves. File → Open Folder… (⌘O) does the same.
• Click Downloads, Desktop or Movies.
• Click Add Folder… to keep a folder you often copy your videos to on the start screen. Right-click it to remove it.

The app also remembers the last 5 folders you scanned. They show under Recent on the start screen, and in File → Open Recent. Right-click a recent folder for Keep on This Screen, Remove from Recent and Clear Recent Folders.

The first time, macOS asks whether Clip Joiner can read files on the card. Click Allow. macOS asks the same for Desktop, Documents and Downloads. The app never reads any of them until you click.

The list

After a scan, the window lists what it found, in two parts.

At the top are the recordings the camera split. A GoPro saves a long recording as chapters, like GX010141.MP4 and GX020141.MP4. A DJI drone starts a new file every few gigabytes. Each recording is one row with a thumbnail, the name of the file it will become (GX010141 joined.MP4), the camera, and a line like “GoPro · 3 files, 11.8 GB, 26 min”. Click Show the 3 files to see its parts.

GoPro recordings start ticked. A DJI drone doesn’t mark which files belong together, so the app explains its guess under the row (“These 2 files look like one recording: the second starts where the first ends. Tick the box if they belong together.”) and leaves it unticked. It never joins a guess on its own.

Below are the other videos, the ones in one piece, like a trail camera’s clips. Each row has a checkbox, a thumbnail, the file name, and a line like “Oct 12, 2026 at 10:46 PM · 1 min · 263.7 MB”. They start unticked. Select All and Select None are in the header.

What else the scan found, like part of another recording or a file that can’t be read, is in an Also found line under the list. Click it for the details.

Preview a video

Click a row and its video plays in a small panel over the bottom right corner of the list. The checkbox and the grip don’t select a row, so ticking and dragging work as before.

• A video in the list plays that file.
• A split recording plays its first file, and the panel’s title says which part it is, like “GX010141.MP4 · part 1 of 3”.
• A row that says Joined and checked plays the joined file.

The video starts on its own with the sound off. The speaker button in the panel’s title turns the sound on. The up and down arrows move to the next row, and Space plays and pauses.

Close the panel with its close button or with Escape. It also closes when its video leaves the list.

When a video can’t be played, the panel says “This video can’t be previewed.” and the video can still be joined.

Tick and join

Tick two or more videos to join them into one. A row appears at the top of the videos for the file they will become, with a line like “7 videos into one · 7 min · 1.8 GB”. Open it to see the videos in the order they’ll be joined.

The Join button says what it will do:

• Join 2 Recordings when only recordings are ticked
• Join 7 Videos into One when only videos are ticked
• Join 2 Recordings and 7 Videos when both are

Each ticked recording becomes its own file. The ticked videos become one more file.

The bar under the list says where the files go: Save joined files to Movies. That’s your Movies folder unless you change it. Click Change… to pick another folder.

Under it, the app adds up the space the joins need: “Needs 1.8 GB. Macintosh HD has 182.4 GB free.” When the disk doesn’t have enough, the line turns red and starts with “Not enough space”, and the Join button stays off until you untick something or choose another disk.

When you save to a folder on the card itself, the bar warns you: “This folder is on the card itself. The joined files will take up space there.”

Clip Joiner never replaces a file. When the name is taken, the row says “Name already used” and explains it: “A file named 2026-10-08.mov is already in Movies. It won’t be replaced.” Click Save as 2026-10-08 2.mov to use the next free name.

While it joins, the bar shows “Joining 1 of 2” with the file’s name, and each row shows its stage: Reading, Copying, then Checking. Cancel stops it and leaves nothing half-done behind.

The order

The videos are listed by the date they were recorded, oldest first, and they’re joined top to bottom. For MP4 and MOV videos that’s the date inside the file. For AVI videos it’s the date of the file.

To change the order:

• Drag a row up or down, using the grip at its right edge.
• Right-click a row and choose Move Up, Move Down, Move to Top or Move to Bottom.

Once a row moved, the header says “in your order”, and Sort by Date puts the date order back. A new scan or Start Over goes back to date order too.

The recordings a camera split can’t be moved. Their order comes from the camera.

The name

The videos you tick are joined into a file named after the day they were recorded, like 2026-10-08.mov. When they were recorded over several days, the name has the first day and the last: 2026-10-08 to 2026-10-15.mov. Moving rows doesn’t change it.

A recording the camera split keeps the camera’s name, like GX010141 joined.MP4.

To call a joined file something else, click Rename… on its row after the join. Type the new name and press Return, or Escape to leave it as it was. The extension stays the same. A name can’t be empty, start with a dot, or contain a slash or a colon. If the name is taken, the app says so and nothing is replaced.

Show in Finder

Every joined row has Show in Finder, which opens the Finder with the joined file selected.

Right-click a video in the list for Show in Finder too. On a recording the camera split, it selects all of its files.

After the join

When a join works, its row says Joined and checked, with Show in Finder, Rename… and Move Originals to Trash… under it. The bar sums up the run, like “7 videos were joined into one and checked, in Movies.” and “Your original files weren’t changed.”

The app writes the joined video under a hidden temporary name. Then it reads it back from the disk and compares it with the originals, piece by piece: the picture, the sound and the camera’s own data. Then it asks macOS to open the video, and its length has to be the length of the originals added together.

Only then does the file get its name. If anything is off, the temporary file is removed and the row says Not joined with the reason. Your originals are where they were.

The joined file keeps the date of the first video, so it sorts by date in the Finder.

Free the card

After a join that says Joined and checked, you can move the originals to the Trash. Click Move Originals to Trash… on the row for that join, or in the bar for every join of the run.

Nothing moves until you confirm. The alert says what’s about to happen, like “Move the 7 original videos to the Trash?”, and Keep Originals is the default button, so Return, Escape and Space never remove anything.

On a memory card, the Trash is on the card. macOS keeps a card’s trashed files in a hidden folder on the card itself, so they keep taking up space there until you empty the Trash. The alert says so: “In the Trash, they stay on NO NAME and keep taking up space there until you empty the Trash.”

When every original is on a card or a drive that can be taken out, the alert adds Delete Now. It frees the space right away, and it can’t be undone. On your Mac’s own disk there’s no Delete Now, only the Trash.

Right before it removes anything, the app looks at the joined file once more. It has to be where it was saved, with the same size and date. If you moved it or edited it in the meantime, the originals stay and the row tells you why: “2026-10-08.mov changed since it was joined, so its originals were kept.” A rename with Rename… is fine, since the app follows the new name.

What moves:

• the files of a recording the camera split
• the videos you ticked and joined
• a drone’s .SRT files, only when they were joined into one

GoPro .THM and .LRV files and every other file stay where they are. A file that can’t be moved is left in place, with macOS’s reason under the row.

After it’s done, the row says Originals in the Trash or Originals deleted, and the videos that moved leave the list. Files in the Trash can still go back with the Finder’s Put Back.

What it reads and what it refuses

Clip Joiner reads MP4, MOV and AVI videos.

AVI videos are the ones trail cameras record. They’re joined into a .mov file, which plays in QuickTime Player. The frames inside are still the camera’s own. AVI and MP4 videos can’t be joined together: “IMAG0001.AVI is an AVI file and GX010141.MP4 isn’t, so they can’t be joined without converting one of them. Join the AVI files on their own.”

An AVI video has to be Motion JPEG, the kind trail cameras write. For another kind the app says why: “The video in IMAG0001.AVI is H.264, not Motion JPEG. This app joins AVI files of Motion JPEG only, because other kinds can’t go into a .mov without changing them.”

Videos of another type are listed and left alone: “The 7 videos here are MKV files. Clip Joiner reads MP4, MOV and AVI files.”

The videos you join have to be recorded with the same settings, like the same picture size. Making different ones fit would mean rebuilding every frame, so the app refuses and names the odd one out.

A GoPro’s GPS and motion data is kept in the joined file. A drone’s .SRT files, which hold the flight data, are merged into one that still lines up with the video. The row then says “The .SRT subtitles were joined and checked too”, with the file’s name.

Clip Joiner doesn’t trim or convert videos. It never changes, renames or removes an original, unless you confirm moving it to the Trash or Delete Now.

Troubleshooting

The folder couldn’t be read

If you clicked Don’t Allow when macOS asked, the window says “Can’t Open Downloads” and “Clip Joiner couldn’t read Downloads. You can allow it in System Settings > Privacy & Security > Files & Folders, then try again.” Click Open System Settings, turn on the folder for Clip Joiner, then click Try Again.

A folder on a drive that isn’t plugged in gives “Clip Joiner couldn’t find Footage. If it’s on a drive, plug the drive in and try again.”

Nothing to Join

The scan found nothing the app can join. The sentence under it says why:

• “No videos were found here.” Check that you picked the right card or folder. A camera usually keeps its videos in a DCIM folder.
• “The 7 videos here are MKV files. Clip Joiner reads MP4, MOV and AVI files.”
• “None of the videos here can be joined as they are. The line below says why.” Open the Also found line.

A recording with a missing chapter

A recording with a missing part can’t be ticked. Its row says “Can’t be joined” and which file to look for: “GX020152.MP4 is missing. This recording has chapters 1 and 3, so it can’t be joined until chapter 2 is back.” Copy that file back to the card’s folder and scan again.

Videos with different settings

The row says Not joined and names the video that doesn’t match, like “IMAG0002.AVI was recorded with different settings than IMAG0001.AVI (the video has 25 frames a second, not 30), so they can’t be joined without compressing them again.” Untick that video and join the others.

Name already used

A file with the same name is already in the folder. Click Save as … under the row to use the next free name, or click Change… to save somewhere else.

Not enough space

The bar says how much the joins need and how much the disk has, and the Join button stays off. Untick something, choose another disk with Change…, or make room on the disk.

A card formatted as FAT32 can’t hold a file over 4 GB, so the app refuses to save a bigger joined file there: “Choose another disk.”