A Google Docs Add-on for more efficiently and effectively highlighting Google Documents.


Custom Highlighters

Never forget what the color of the highlighted text means by creating custom sets of highlighters to use across your Google Documents. Create different sets of highlighters for different tasks and use them whenever you need them.


Organize and Analyze

Understand what your highlighted text means more efficiently by extracting highlighted text from Google Documents and grouping them by their color or organizing them by their original order.


Share and Collaborate

Work with others using the same set of highlighters (colors and labels) on any Google Document by sharing your highlighter sets with other users of this add-on. Communicate with others through your highlighters.

What's Highlight Tool?

Highlight Tool is a Google Docs Add-on that enables its users to effectively highlight their Google Docs, extract highlighted text, and share and collaborate with other users through sharing their highlighter sets.

Highlight Tool is made for students and educators at its very core. It started out as a high school Computer Science club project for a teacher to help her students organize and highlight their Google Docs. Since then, it has evolved to support the needs of many other educators through their feedback and feature requests.

Use cases


Match a highlighted text's color with its label

Never forget what the color of your highlighted text means by creating custom highlighters. Users can create a highlighters, which are color and label pairs, and store them for future use.

Now it's easy to know that dark green means thesis, yellow is evidence, red is commentary, and navy blue is conclusion. The image on the right shows how easy it is to match the colors with the labels using the sidebar.

Use this for correcting grammar mistakes, identifying the structure of an essay, tagging important facts, and much more.


Extract and analyze your highlighted text

Isolate the most important parts of your Google Doc by extracting its highlighted text. Users can group the highlighted text by their highlighted color or by their original order. It's a lot easier to analyze a large document in small groups at a time.

Following from the previous example, now we can extract the highlighted text. If we extract it by its original order we get the structure or outline of an essay. If we extract it by color we can analyze and compare and contrast the different pieces of evidence against each other.

Use this functionality for tasks from the previous part and more by isolating your problem and analyzing pieces of it.


Collaborate with users and share highlighters

Share your custom highlighters with other users and be on the same page. Users can open the same Google Doc, open up the add-on, and instantly understand what each color means. Eliminate the confusion by this add-on's sharing capabilities.

Educators and teachers can prepare a custom set of highlighters the night before and share it with their students the following day. That custom set of highlighters is up to the power of the user who knows their area the best. On the right, a grammar correction set is made and can be shared with many other users.

Use this communicating with users on tasks where understanding what the color of each highlighted text means such as denoting grammar mistakes and identifying key topics.


<Insert your use case>

As a user with your own set of problems you know your own needs the best. I hope by building this add-on you'll be able to use this tool and its features that have grown from suggestions from users like yourself to help solve the task at hand.

COPPA Compliance/Privacy Policy

This Google Docs Add-on:

This Google Docs Add-on requests two sensitive privacy scopes for the following reasons:

User data:

I made this as a student in high school in 2015 for my Social Studies teacher. I don't have a need for your data.

The code is made publically available on my github.



First start the add-on once in a Google Document by performing the following actions: Add-ons > Highlight Tool > Start.

To highlight text, select some text in the Google Document and click one of the highlighters in the add-on sidebar on the right.

To unhighlight text, select the desired text in the Google Document and click the Un-highlight button.

To create more highlighters (color and label pairs), click on Highlighter Library.


Start the Highlighter Library by clicking Highlighter Library in the add-on sidebar.


  • Highlighter is a color label pair as seen in the add-on sidebar.
  • Highlighter Set is a set of highlighters along with a name.
  • Highlighter Library is a collection of highlighter sets with a currently select set.

Click the blue Save button once changes have been made to save the changes. Click the grey Cancel button if those changes should not be saved.


To create a highlighter set, click the green New set button.

To create a new highlighter for a set, click the + button located on the top row of the corresponding set.

To select a color for the highlighter, click the rectangular colored box. To select a label for the highlighter, type in the desired label in the input text box.


To delete a highlighter set, click the red Trash Can button located on the top row of the corresponding set.

To delete a highlighter from a set, click the - button located next to the highlighter,


To reorder highlighter sets, click the drag handle (looks like an arrow going up and an arrow going down) and drag it to the desired order.

To reorder highlighters within a set, perform a similar action, click the drag handle and drag it within the set to the desired order.


To duplicate a highlighter set (in order to avoid starting from scratch), click on the grey copy button (looks like two documents where one is overlapped) next to the + button.

To minimize a highlighter set click the chevron button (looks like an arrow). To unminimize the highlighter set, click on the same button.


Extract highlighted text from a Google Document by opening the add-on in the desired doc and click one of the two Extract located at the bottom of the add-on sidebar.

Order of extracted text

  • By chrono orders the highlighted text in their original order.
  • By color groups the highlighted text by their highlighted color.


Share highlighter sets with other users by performing the following actions: Add-ons > Highlight Tool > Export Library.

Use other users' highlighter sets by performing the following actions: Add-ons > Highlight Tool > Import Library while in a Google Document with the highlighter share blocks generated by the export feature.

Share blocks

These share blocks can be copy and pasted to any Google Document and can be imported into anyone's highlighter library. Use these to collaborate with others and be on the same page.


Settings are a way to control the behavior of the add-on to fine tune it to your needs.

Auto import

If this setting is set to true, then whenever the add-on is opened, the add-on will check for any share blocks in the current Google Document. If there are then a dialog will pop up prompting the user if they want to import these highlighter sets into their highlighter library.

Contact me at jlchin3 (@) gmail.com for any suggestions, errors, or help concerning the add-on.