What’s an ACO File for and How to Open Them Online?


ACO files are color swatch files created by Adobe software. These files can be used to store colors for use in Adobe Photoshop, Illustrator, and InDesign. However, you don’t need Adobe software to use ACO files. There are a number of online ACO viewers that allow you to open and view these files without any Adobe software. This blog post will show you how to use an online ACO viewer to open ACO files for free even if you don’t have Adobe software.

What is an ACO File?

ACO file is short for Adobe Color swatch file. These files contain color swatches that can be used with Adobe Photoshop, Illustrator, and InDesign. ACO files are saved in binary format and usually have the .aco extension. In addition to color swatches, these files may also include tints, gradients, and patterns.

ACO files can be created manually or exported from existing documents. For example, if you have a Photoshop document with a custom color palette, you can export that palette as an ACO file. This can be useful if you want to use the same colors in another program like Illustrator or InDesign.

How to Use an Online ACO Viewer?

There are a number of online ACO viewers that allow you to open these files without any Adobe software. Most of these ACO viewer tools are free to use and don’t require registration or installation.

Screenshot for ACO file viewer tutorial
The screenshot is showing the results of uploading an ACO file to the ACO viewer tool.

You can, of course, choose any that you like but in this quick tutorial I used the ACO file viewer from Google App Spot because it’s very appealing, functional, and not packed with ads. So how do you use it?

Steps to open the ACO file online

Here are the very quick steps you need to know in order to open an ACO file online in a free tool.

  1. Load the online ACO file viewer.
  2. Drag your file in the upload box or use the upload dialogue to find your ACO file on your computer.
  3. Wait for a second and you’ll see the contents of the ACO file below.

The results that you’ll get will be a list of colors that are part of the Adobe color palette file along with a preview box, the hex code for the color, as well as a bit of CSS on how it could be used to display the contents of the file elsewhere.

This is very useful for everybody who needs to work with the ACO file format quickly but doesn’t have access to Adobe software at that given time. Some people also just work with free photo editors or free online design tools like Canva. All those people can simply extract the hex codes of the color palette and complete their task without making any step inside the Adobe software ecosystem.

How to obtain ACO files?

Finance Mobile App Design by Ghulam Rasool - Dribbble screenshot for ACO file viewer tutorial
Image: Use the download feature of Dribbble to extract an ACO file from a design (example design by Ghulam Rasool on Dribbble)

In case you want to try this out but have no idea where you could obtain an ACO file you could navigate to Dribbble and find a design there, which often lets you also download the associated ACO file. For instance, for the screenshots in the tutorial, we used the design “Finance Mobile App Design” by Ghulam Rasool. When hovering the image you can see a little icon appear in the lower left corner. If you expand that icon, it will show the colors used, and they give you an option to download the ACO file which you can then use with an online ACO file viewer.


As we’ve seen, ACO files are color swatch files created by Adobe software. However, you don’t need Adobe software to use these files – many ACO viewer tools allow you to open them without any Adobe software installed on your computer. ACO files are useful for storing colors for use in multiple Adobe programs, and you can even export them from existing documents.

In case you do have Adobe software and don’t want to use a free online ACO or ASE (alternative format) tool, please check the video below from the Ghostly Pixels YouTube channel, in which they explain how you can open the files in Photoshop.

YouTube: Open ASE and ASO file format color palette’s in Photoshop

Photo credit: The feature image has been done by Joy Seulay. The screenshots for the tutorial have been taken by Christopher Isak for TechAcute and are owned by the respective designers and tool developers as credited in the text.

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Christopher Isak
Christopher Isakhttps://techacute.com
Hi there and thanks for reading my article! I'm Chris the founder of TechAcute. I write about technology news and share experiences from my life in the enterprise world. Drop by on Twitter and say 'hi' sometime. ;)
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