Split screens and video walls show up everywhere in modern editing, from a side by side reaction in a vertical Instagram post to a four up montage in a brand spot. The look is simple, but building it by hand in After Effects is not. You scale each clip, draw masks, nudge positions, and redo it all the moment a comp changes aspect ratio. GridMaker turns that into a couple of clicks.
GridMaker is a Filmit plugin for After Effects that grids your footage automatically. Drop in your clips, pick columns or rows, and it builds the split screen, masks and all, fitting whatever composition you are in. This guide covers installing it, grabbing footage with Sourcer, building splits and stacked rows, pre composing cells to swap footage later, and auto fitting to a vertical comp for Instagram. Premiere Pro support is here too, with Final Cut Pro and DaVinci Resolve on the way.
This video may reference an older version of GridMaker. Features and UI may have changed since recording.
How to install GridMaker in After Effects
GridMaker installs through Filmit Studio, the free companion app for Windows and macOS that manages every Filmit plugin from one place. GridMaker is an After Effects plugin, so once installed you open it like any other extension.
- Create a free account on filmit.io and open your dashboard.
- Download Filmit Studio for Windows or macOS from your dashboard and install it.
- Open Filmit Studio, go to My Tools, and click install on the GridMaker card.
- Open After Effects and find GridMaker under the Window menu, in Extensions.
That is the whole setup. Filmit Studio handles the download and install, and the panel shows up in your Extensions list ready to go.
Pro Tip: If GridMaker is not in your Extensions list after installing, fully quit After Effects and reopen it. Adobe only scans for new extensions on launch, so a restart is usually all a freshly installed panel needs to appear.
How to grab two clips with Sourcer
A split screen needs at least two pieces of footage. You can use your own clips, but in the tutorial the footage comes from Sourcer, another Filmit plugin that searches royalty free footage and inserts it without leaving your editor, in both After Effects and Premiere Pro.
- Open Sourcer from the Window menu, in Extensions.
- Type a search, for example dog, and insert the clip you want.
- Search again, for example cat, and insert a second clip.
Two clips in, a dog and a cute cat, and you have everything GridMaker needs. Because the footage is royalty free, you can use it in client work without chasing licenses.
Pro Tip: Stage your clips before opening GridMaker, then select them in the timeline. GridMaker grids whatever is selected, so getting the footage in place first makes the build a single click.
How to build a side by side split screen
This is where GridMaker earns its place. With both clips in the comp, select them and choose two columns. GridMaker grids the footage automatically, creates the mask for each cell, and lines the two clips up side by side. No scaling, no drawing masks, no nudging positions. The split is built the moment you click.
The same approach scales up. Add more clips and a layout with more columns, and GridMaker fits them all into an even grid, which is how you get a video wall rather than a simple two up.
Pro Tip: Not happy with how a clip is framed inside its panel? You do not have to rebuild the grid. Select that cell, grab the footage, and slide it up or down to reframe within the mask while the layout stays put.
How to stack clips into rows
Columns put your clips side by side, but a lot of layouts call for the opposite. Turn off the previous grid, select your clips again, and choose two rows. GridMaker builds the masks the same way and stacks the footage top and bottom instead of left and right. Which one you reach for depends on your footage and format. Here is how they compare:
Columns read best on a horizontal comp, while stacked rows are the look you see all over Instagram on a vertical one. The buttons sit right next to each other, so trying both takes seconds.
How to pre comp cells so you can swap footage later
Most split screens go through a few revisions before they are final, and you rarely want to rebuild the grid each time. GridMaker has a pre comp layers option for exactly this. Turn it on before you grid, and GridMaker wraps each cell in its own pre composition.
With cells pre composed, swapping footage is painless. Open any cell, drop in a new clip, and the layout stays exactly as it was. The masks, positions, and spacing all hold, so you are editing the contents of a panel rather than reconstructing the split. That is the difference between a layout you can iterate on and one you are stuck with.
Pro Tip: Decide on pre comp before you build, not after. Turning the option on from the start gives you cells you can open and swap freely, which saves you from tearing down a finished split screen just to change one clip.
How to auto fit a split screen to a vertical comp for Instagram
Vertical formats are where this really pays off. Switch over to a vertical composition and paste your footage in. GridMaker automatically understands your composition and works out the math behind the scenes to make the split fit perfectly, so you recalculate nothing by hand.
Select both clips and choose two columns for a vertical side by side, or two rows for the stacked look you see constantly on Instagram. The same buttons you used on a horizontal comp just work, because GridMaker fits the grid to whatever aspect ratio you hand it.
Pro Tip: Build the split in the comp that matches your final delivery. Because GridMaker fits the grid to the active composition, a correctly sized vertical comp means your Instagram or TikTok split is framed right from the first click.
What is coming in GridMaker v2
GridMaker is on version 1.3 today, and version 2 is in the works as a major addition to the Filmit suite, with more attributes and features for building grids, split screens, and video walls. To follow along or weigh in on what you want, open settings inside GridMaker and join the Filmit Discord from there, or use the community forum on the website to chat with me directly.
Key takeaways
GridMaker turns split screens and video walls from a manual masking job into a couple of clicks inside After Effects, fitting every grid to your comp.
Select your clips, pick columns or rows, and GridMaker creates the masks and positions every cell.
Side by side for wide comps, stacked for vertical splits, switched with neighboring buttons.
Turn on pre comp layers and replace the clip in any cell without rebuilding the grid.
GridMaker reads your composition and auto fits the split to vertical comps for Instagram and TikTok.
Pull royalty free clips with Sourcer and drop them straight into a grid.
Why a dedicated grid panel is worth it
I built GridMaker because split screens were one of those tasks that looked trivial and never were. Every time a client wanted a side by side, I would scale two clips, draw masks, line up the edges, and then the comp would change to vertical and I would do it all over. It is fiddly, repetitive work that has nothing to do with the idea you are trying to land on screen.
Letting the plugin handle the masking and the math changes how you work, not just how long it takes. When a split screen is a click away, you try three layouts instead of committing to the first because rebuilding is a chore. That is the point: the layout stops being the obstacle, and you get back to deciding what belongs in the frame.
Take your editing workflow further with Filmit
GridMaker is one piece of a larger toolkit built to remove the repetitive parts of editing in After Effects and Premiere Pro. The Filmit for Editors suite covers grids and split screens, stock footage sourcing, GIF insertion, project organization, and more, all installed through Filmit Studio.
If you need footage to fill your grid, Sourcer searches royalty free libraries and inserts clips straight into your project, exactly how the dog and cat footage lands in this tutorial. And GridMaker turns those clips into split screens and video walls in one click, fit to whatever comp you are in. Every tool runs under one Filmit subscription, always updated.
