How to install and run After Effects scripts (.jsx and ScriptUI)

What is an After Effects script, and how is it different from a plug-in?

A script is a plain-text file of code, usually saved as .jsx, that runs inside After Effects and does steps you would otherwise click through by hand. It is not an effect plug-in and it is not an extension panel. That difference decides how you install it.

Adobe describes After Effects as a motion design and visual effects app for animating text, graphics and illustrations and for compositing visual effects. Scripts sit on top of the app and automate work inside it.

Three file types get mixed up all the time: .aex, .jsx and .zxp. Our guide to plugin vs script vs extension covers what each one is, where each installs and why a panel goes missing. If your download is a .aex, follow how to install After Effects plugins instead.

Scripts come in two shapes:

• Some run once, do their job and finish.
• Others open a window of buttons that you keep open while you work. Developers call these ScriptUI panels.

The readme tells you which kind you have, and the kind can change where the file goes.

mouzeclick's own After Effects tools, which we make, are a third thing. They are extensions: panels that open under Window › Extensions and are installed by the mouzeclick app. You never copy them into a scripts folder.

How do I install an After Effects script, step by step?

Install a script in eight checks, in this order. Each one rules out a cause of failure before you meet it.

1. Check the file type. A script is a .jsx file. If the download also holds a .aex, that part is a plug-in. A .zxp is an extension. Sort the files before you copy anything.
2. Read the readme and the product page. Note three things: the After Effects versions the developer lists, whether the script runs once or opens a panel, and any setting it asks you to turn on.
3. Match the version. Compare the developer's list with the After Effects you open every day. If your version isn't listed, ask the developer before you install.
4. Save your project and quit After Effects. It takes seconds and removes one variable if you have to troubleshoot later.
5. Copy the files to the folder the readme names. Check that folder against Adobe's Scripts help page for your system. A script that opens its own panel may want a different folder from one that runs once, and the readme says which.
6. Switch on a permission only if the readme asks for one. Use the exact setting name it gives. The section on allowing scripts below explains why.
7. Open After Effects and test on a copy. Duplicate the project or the comp, run the script once, then undo and check that everything comes back.
8. Keep the download. Put the original zip and the readme in one folder named with the script and its version. A reinstall after an After Effects upgrade then starts from the right files.

If the script comes with its own installer, the developer's instructions replace steps 4 to 6. Still keep the readme.

Where is the After Effects scripts folder?

Use the folder the script's readme names, and check it against Adobe's Scripts help page for your version. We checked that page on 3 November 2026. The text we could capture didn't include the Windows or macOS paths, so this page doesn't print them from memory. A wrong path costs you more time than a missing one.

Three habits help you get the folder right the first time:

• Use the readme's folder, then check it. The developer wrote the readme for that script. If the readme and Adobe's page disagree on the folder, go with Adobe's page for your version. For anything specific to the script, go with the readme.
• Know which After Effects you are installing into. If you have more than one version installed, note the one you work in and check that the developer supports it.
• Read version lists closely. KBar3's page says it is for After Effects CC 2019 and above, but its compatibility list shows 2026, 2025, 2024, 2023 and 2022 (checked 3 November 2026). When two lines on a page differ, plan around the narrower one.

Presets are a separate case. Animation presets are .ffx files, and installing After Effects presets has its own guide.

How do I allow scripts to write files and access the network in After Effects?

Turn on a scripting permission only when a script you trust needs it and its readme asks for it. Use the exact setting name the readme gives, and check it against Adobe's Scripts help page for your version.

Some scripts only move layers, keyframes or names inside your project. Others need more:

• saving a file to disk, such as a report or an export list
• reading a file you pick, such as a CSV of names or an SRT
• talking to a server, for a licence check or an update

The readme for a script like this may ask you to turn on a setting first. The setting's exact name and menu path weren't in the Adobe text we could check on 3 November 2026. Copy the wording from the readme and check it on Adobe's page rather than hunting through settings at random.

Keep it tidy:

• Turn the permission on for the scripts that need it, from developers whose pages you trust.
• If a script fails at the moment it saves, exports or loads something, check this setting before anything else.
• If a script that only renames layers asks for file and network access, ask the developer why before you allow it.

Why won't my After Effects script run?

Most scripts that won't run fail for one of six reasons. Work down this list in order:

1. Wrong file type. A .aex or a .zxp is not a script. It won't behave like one wherever you put it.
2. Wrong version. Compare the developer's list with the After Effects you run. A script built for newer versions may not load in an older one, and the reverse can happen too.
3. Wrong folder. Check the readme's folder against Adobe's Scripts page for your system. Rule out a panel-type script sitting in a run-once location, or the other way round.
4. Missing permission. If it fails when it saves, exports or loads something, check the setting the readme names.
5. Broken text. If you or anyone else edited the file, look for curly quotes where straight ones should be. Adobe documents a related Mac problem. If you edit the After Effects keyboard shortcuts file in TextEdit on Mac OS X 10.9 or later, After Effects shows an error the next time it starts. Adobe's fix is to disable Smart Quotes, and that setting is worth turning off before you edit any script file in TextEdit.
6. A skipped step. Look for any licence, companion file or restart step the readme mentions, and reread it top to bottom once.

Still stuck? Run the script in a new, empty project to rule out your project file. Then send the developer your After Effects version, your system and the exact message on screen. If After Effects itself is unstable, check your computer against Adobe's system requirements page.

If a mouzeclick panel is the one missing, follow these steps:

1. Press Install After Effects bridge on the app's Tool wheel page.
2. Restart After Effects.
3. Open the panel from Window › Extensions.
4. Keep mouzeclick running while you work.

How do I write my first After Effects script?

Start with one small job you repeat every day and write its steps in plain words. Check whether an expression or a preset already does it. Only then write code, with the After Effects Scripting Guide open beside you.

1. Pick one job. Choose a task with a clear end, such as adding a null above the selected layer or renaming a set of layers. Leave the full toolkit for later.
2. Write the steps as sentences. Each sentence becomes something you look up: which layer, which property, what value.
3. Ask whether you need a script at all. If a value should move by itself over time, that is often an expression. Start with how to add expressions in After Effects or a ready set from our After Effects expressions library. A look you reuse can be an animation preset. Adobe describes presets as reusable configurations of layer properties and animations.
4. Use a plain-text code editor. Don't use a word processor. Save the file with the .jsx extension. On a Mac, if you use TextEdit, turn off Smart Quotes first: it is the same fix Adobe gives for its shortcuts file.
5. Look up every object in the Scripting Guide. Keep the After Effects Scripting Guide open as you write. Don't guess names: a typo can stop the script.
6. Test on a copy. Save, duplicate the comp, run the script, undo, and check the result. Fix one thing at a time.
7. Give it a button. Once it works, put it on a toolbar or a mouse button, as the next two sections show.

We don't include sample code on this page. Every line we publish about After Effects comes from a source we checked on the day, and for code you should work from the Scripting Guide. For scripts other editors already wrote and share, see what Reddit recommends for After Effects scripts, summarised from 13 threads.

How do I run scripts from a toolbar instead of a menu?

Put the script on a toolbar button. KBar3 and mouzerun, which we make, both turn a script into a one-click button inside After Effects. They differ in what else a button can do.

KBar3

KBar3 builds customizable, shareable toolbars for After Effects CC 2019 and above. Its published feature list includes:

• buttons for effects and presets, menu commands, extensions, expressions, scripts and scriptlets, and shell commands
• up to 4 toolbars with keyboard modifiers, and up to 4 toolbar windows open at once
• 600+ icons, or your own PNG or SVG files
• bulk import and export of buttons

The latest version in its history is 3.1.3, dated 15 November 2025. On 3 November 2026 the page showed upgrade prices only: $20 for KBar2 users and $30 for KBar1 users, shown after you log in to the same account. The full price and the supported systems were not published in what we checked. Best for: a dedicated After Effects toolbar with lots of icons.

mouzerun (we make it)

mouzerun is a panel of your own one-click buttons in five kinds: a script, an expression, an animation preset, a menu command or a keyframe ease. It comes with six starter buttons, and you can export and import your buttons. It is one of mouzeclick's 15 After Effects extensions and runs on Windows and Mac. The mouzerun feature page lists all 31 items. Best for: script buttons inside a plan that also puts your shortcuts on the mouse.

Where KBar is the better pick

If you want a toolbar app and nothing else, KBar is the more focused choice. Its published list covers shell commands, extensions as buttons, 600+ icons, up to 4 toolbar windows and toolbars switched by modifier keys. mouzerun's published list mentions none of those. Our KBar alternative comparison puts the two side by side.

How do I put an After Effects script on a mouse button?

First give the script a key combination in the tool you launch it from, if that tool allows one. Then map that combination to a mouse button in mouzeclick's mouse app. The app runs on Windows and Mac and works with any mouse your computer sees, wired, wireless or Bluetooth, with no driver.

We couldn't confirm from Adobe's pages on 3 November 2026 how After Effects itself assigns keyboard shortcuts to scripts. Check your script's readme or your toolbar tool first. For the app's own keys, see the After Effects keyboard shortcuts list.

1. Open the After Effects profile. Each app gets its own profile, and the editors come with ready-made ones.
2. Choose where the script goes. Each button has eleven slots: tap, hold and move in four directions, a chord with another button, or hold and scroll. Buttons work per app, so Mouse 4 can run your script in After Effects and do something else in every other app. It changes the moment you switch windows.
3. Record the shortcut. Record the script's key combination as the action for that slot. A hotkey can also block a combination an app keeps stealing.
4. Chain steps if one key isn't enough. A macro chains keys, clicks, waits, typed text and launches.
5. Test it on a copy of your project before you use it on real work.

The library has 309 built-in shortcuts on Windows, 44 of them for After Effects, and your own hotkeys and macros sit beside them in the picker.

On a Mac, Apple hasn't notarized the app yet, so you allow it once. Then turn it on under Accessibility and Input Monitoring; installing mouzeclick on a Mac has the four steps. On Windows, apps running as administrator ignore apps that are not elevated, so if After Effects runs elevated, pick Restart as administrator in the tray menu. Ctrl+Alt+F12 stops mouzeclick at once on Windows.

Where mouzeclick fits (we make it)

We make mouzeclick, so read this section as ours. It doesn't replace a script you rely on. It gives that script a button and a mouse move, and it adds ready tools of its own.

• Buttons: mouzerun runs your scripts, expressions, presets, menu commands and keyframe eases in one click, on Windows and Mac.
• Ready tools: mouzekit is sold as 28 After Effects tools in 7 groups. Each tool is one undo step, and its expressions work in any language of After Effects.
• The mouse: per-app buttons, gestures, macros and three wheels. The After Effects Tool wheel holds 114 tools in 13 groups and opens with F10 or a held right button. It needs the bridge, installed once from the app's Tool wheel page.
• Windows only: the After Effects workspace, with 800+ tools, presets and templates, including a Library of 25 recommended expressions. The workspaces are part of mouzeclick on Windows, and the Mac app does not include them. Captions, Retakes, cloud sync and in-app updates are Windows only too.

All of it comes in one plan, with every part listed on the extensions page. It costs $25 a month, $249 a year, or $499 once for one of the first 100 lifetime keys; see mouzeclick pricing. The free trial is 3 days with no card, and every Premiere Pro and After Effects tool works fully during it. mouzeclick needs an internet connection while it runs. If the connection drops, the shortcuts pause and the mouse acts normally until it returns.

Questions people ask

Sources

Checked on 2026-11-03. Prices and features change: each link goes to the maker's own page.

1. Adobe: After Effects product page (what it is, single-app and teams prices, checked 3 Nov 2026)
2. Adobe: Creative Cloud plans, India price (checked 3 Nov 2026)
3. Adobe: After Effects free trial (platforms, refund window, membership)
4. Adobe Help: Scripts in After Effects
5. After Effects Scripting Guide
6. Adobe Help: error after editing the shortcuts file in TextEdit (Smart Quotes)
7. Adobe Help: Effects and animation presets overview
8. Adobe Help: After Effects system requirements
9. KBar3 on aescripts + aeplugins (features, versions, upgrade prices, checked 3 Nov 2026)

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