Beginner guide to coding with Google Apps Script

What is Google Apps Script or G.A.S.?

It’s a cloud based scripting language for extending the functionality of Google Apps and building lightweight web-based applications.

What does this mean in practice: It’s a coding language where you can write small programs performing custom behaviors that go beyond the standard features of Google Apps. The code is stored and executed on Google’s servers.

It means you can do cool stuff like automating repetitive tasks, creating, modifying and emailing documents to people, and linking up your Google Sheets to other data sources. Heck, you can even build complex web forms, use a Google Sheet as your database, programatically create charts and publish it all to the web. In other words, you can build fully featured, lightweight web applications.

New course coming soon…

Apps Script course launching in December 2018!!!

Apps Script Blastoff course
Apps Script Blastoff! is a free, introductory course teaching Google Apps Script from scratch. Read more here >>

Writing your first Google Apps Script

So let’s go ahead and write our first, extremely basic program, the classic “Hello world” program beloved of computer teaching departments the world over.

In this Google Sheets script tutorial, we’re going to write a script that is bound to our Google Sheet, or you might say contained within our Google Sheet. This is known in the jargon as a container-bound script.

Begin by creating a new Google Sheet.

Then click the menu Tools > Script editor... to open a new tab with the code editor window.

This will open a new tab in your browser, which is the Google Apps Script editor window:

Google Apps Script editor window

By default, it’ll open with a single Google Script file ( and a default code block, myFunction():

In the code window, between the curly braces after the function myFunction() syntax, write the following line of code so you have this in your code window:

Your code window should now look like this:

Google Sheets script tutorial editor menu

Next hit the run button (the black triangle), which prompts you to authorize the app to run, as shown in the following image:

Google Apps Script Authorization

Clicking Continue pops up another window in turn, showing what permissions your app needs to run. In this instance the app wants to view and manage your spreadsheets in Google Drive, so click Allow (otherwise your script won’t be able to interact with your spreadsheet or do anything):

Google Apps Script Authorization


Google have introduced new security protections to reduce risk from unverified apps, which affects the workflow when we first authorize our own apps.

When your first run your apps script, you may see the “app isn’t verified” screen and warnings about whether you want to continue.

In our case, since we are the creator of the app, we know it’s safe so we do want to continue. Furthermore, the apps script projects in this post are not intended to be published publicly for other users, so we don’t need to submit it to Google for review (although if you want to do that, here’s more information).

Click the “Advanced” button in the bottom left of the review permissions pop-up, and then click the “Go to Starter Script Code (unsafe)” at the bottom of the next screen to continue. Then type in the words “Continue” on the next screen, click Next, and finally review the permissions and click “ALLOW”, as shown in this image (showing different script):

More information can be found in this detailed blog post from Google Developer Expert Martin Hawksey.

Next, GAS will show you two status messages to tell you what’s happening.

First this one:

GAS execute script

And then this one:

GAS execute status 2

If anything goes wrong with your code, this is stage when you’d see a warning message (instead of the yellow message, you’ll get a red box with an error message in it).

Now, assuming you got those two yellow status messages and they’ve both automatically disappeared from view, then your program has run successfully. Click back on the browser tab with your spreadsheet (most likely the tab to the left of the one we’re in).

You should see the output of your program, a message box popup with the classic “Hello world!” message:

Google Apps Script output hello world

Click on Ok to dismiss.

Great job! You’ve now written your first apps script program.


Before we continue, let’s rename our function to something more meaningful. At present, it’s called myFunction which is the default, generic name generated by Google. Every time I want to call this function (i.e. run it to do something) I would write myFunction(). This isn’t very descriptive, so let’s rename it to helloWorld(), which gives us some context.

So change your code in line 1 from this:

to this:

Note, it’s convention in Apps Script to use the CamelCase naming convention, starting with a lowercase letter. Hence, we name our function helloWorld, with a lowercase h at the start of hello and an uppercase W at the start of World.

Adding a custom menu

In its current form, our program is pretty useless for many reasons, not least because we can only run it from the script editor window and not from our spreadsheet. So let’s fix that by adding a custom menu to the menu bar of our spreadsheet, so that a user can run the script within the spreadsheet without needing to open up the editor window.

This is actually surprisingly easy to do, requiring only a few lines of code. Add the following 6 lines of code into the editor window, above the helloWorld() function we created above, as shown here:

If you look back at your spreadsheet tab in the browser now, nothing will have changed. You won’t have the custom menu there yet. We need to re-open our spreadsheet (refresh it) or run our onOpen() script first, for the menu to show up.

To run onOpen() from the editor window, first select the onOpen function as shown in this image:

Google Apps Script custom menu

Once you’ve selected the onOpen function, the small triangle button will change from light gray to black, meaning it can be clicked to run your chosen function:

Run function

Now, when you return to your spreadsheet you’ll see a new menu on the right side of the Help option, called My Custom Menu. Click on it and it’ll open up to show a choice to run your Hello World program:

Custom menu

My own journey into Apps Script

My friend Julian, from Measure School, interviewed me recently (May 2017) about my journey into Apps Script and my thoughts on getting started:

Google Sheets script tutorial: more examples

Custom function/maps example

Let’s create a custom function with Apps Script, and also demonstrate the use of the Maps Service. We’ll be creating a small custom function that calculates the driving distance between two points, based on Google Maps Service driving estimates.

The goal is to be able to have two place-names in our spreadsheet, and type the new function in a new cell to get the distance, as follows:

GAS custom function for maps

The solution should be:

GAS custom map function output

Copy the following code into the Apps Script editor window and save. First time, you’ll need to run the script once from the editor window and click “Allow” to ensure the script can interact with your spreadsheet.

Saving social media data

Let’s take a look at another simple use case for this Google Sheets script tutorial.

Here, I’ve setup an importxml function to extract the number of followers a specific social media channel has (e.g. in this case a Reddit channel), and I want to save copy of that number at periodic intervals, like so:

save data in google sheet

In this script, I’ve created a custom menu (as we did above) to run my main function. The main function, saveData(), copies the top row of my spreadsheet (the live data) and pastes it to the next blank line below my current data range as text, thereby “saving” a snapshot in time.

The code for this example is:

See here for a full step-by-step guide to creating and running this script.

Google Apps Script example in Google Docs

GAS is by no means confined to Sheets only, and is equally applicable in the Docs environment. Here’s a quick example of a script that inserts a specific symbol or text string into your Doc wherever your cursor is:

Google Docs Apps Script

We do this using Google App Scripts as follows:

1. Create a new Google Doc

2. Open script editor from the menu: Tools > Script editor...

3. Click on: Create script for > Blank Project

Google Apps script menu

4. In the newly opened Script tab, remove all of the boilerplate code (the myFunction code block)

5. Copy in the following code:

6. You can change the special character in this line

var element = cursor.insertText('§§');

to whatever you want it to be, e.g.

var element = cursor.insertText('( ͡° ͜ʖ ͡°)');

7. Click Save and give your script project a name (doesn’t affect the running so call it what you want e.g. Insert Symbol)

8. Run the script for the first time by clicking on the menu: Run > onOpen

9. Google will recognize the script is not yet authorized and ask you if you want to continue. Click Continue

10. Since this the first run of the script, Google Docs asks you to authorize the script (I called my script “test” which you can see below):

Docs Apps Script Auth

11. Click Allow

12. Return to your Google Doc now.

13. You’ll have a new menu option, so click on it:
My Custom Menu > Insert Symbol

14. Click on Insert Symbol and you should see the symbol inserted wherever your cursor is.

Use the Logger class

Use the Logger class to output text messages to the log files, to help debug code.

The log files can be accessed after the program has finished running, by going to View > Show Logs (or Cmd + Enter, or Ctrl + Enter (on PC)).

The syntax in its most basic form is Logger.log(something in here). This records the value(s) of variable(s) at different steps of your program.

For example, add this script to a code file your editor window:

Run the script in the editor window, then View > Show Logs and you should see:

logger output

Real world examples from my own work

I’ve only scratched the surface of the outermost epidermis, not even millimeters deep, of what’s possible using GAS to extend the Google Apps experience.

Here’s a couple of interesting projects I’m working on:

1) A Sheets/web-app consisting of a custom web form that feeds data into a Google Sheet (including uploading images to Drive and showing thumbnails in the spreadsheet), then creates a PDF copy of the data in the spreadsheet and automatically emails it to the users. And with all the data in a master Google Sheet, it’s possible to perform data analysis, build dashboards showing data in real-time and share/collaborate with other users.

2) A dashboard that connects to a Google Analytics account, pulls in social media data, checks the website status and emails the user if it goes down, and emails a summary screenshot as a PDF at the end of each day.

web dashboard

3) A marking template that can send scores/feedback to students with a single click from within Google Sheets. Check out the how-to post I wrote.

Send data from Google Sheets to Slack

Further Resources

Imagination and patience to learn are the only limits to what you can do and where you can go with GAS. I hope you feel inspired to try extending your Sheets and Docs and automate those boring, repetitive tasks!

For further reading, I’ve created this list of resources for information and inspiration:

Apps Script References

Start writing more advanced scripts with the official Apps Script starter guide – a more advanced Hello World program!

Official Google Documentation

Google Apps Developer Blog

Google Apps Script for Developers Training Video Course from O’Reilly

Collection of great blog posts relating to GAS

Integrating Google Apps Script with Slack

Using Google Sheets and GAS as a backend database

Alexa rank checker with email notifications in Google sheets

How to Create Custom Functions in Google Sheets

List of some popular Apps Script projects


Google Docs Help Forum

Google Apps Script G+ community

Desktop Liberation Apps Script community from Bruce Mcpherson

Stack Overflow GAS questions

Google Apps Script Experts

Zig Mandel (GDE)

Bruce Mcpherson (GDE)

Antonio Guzmán Fernández (GDE)

Martin Hawksey (GDE)

Ivan Kutil (GDE)

Romain Vialard (GDE)

James Ferreira (GDE)

Andrew Stillman (GDE)

Andrew Roberts

Amit Agarwal

GDE – Google Developer Experts are experts in their chosen fields (in this case GAS) and recognized by Google for their outstanding contributions. More info here.

Books and other miscellaneous tips

Going GAS book

Going GAS by Bruce Mcpherson is a newly published (i.e. bang up-to-date as of April 2016) book covering the entire GAS ecosystem, with a specific focus on making the transition from Office/VBA into Google Apps/GAS. Even if you don’t use Office or VBA much or at all, it’s still a very useful resource. It’s been a few years since I’ve done any serious VBA work, but I still found the book very helpful and a great overview of the GAS environment.

learning gas book

Learning Google Apps Script by Ramalingam Ganapathy is another brand new Google Apps Script book, intended for learning Apps Script. I haven’t used this particular book.

Google Sheets Programming With Google Apps Script by Michael Maguire is an ebook available through leanpub. I haven’t used this particular book.

I believe other Google Sheets books are older and therefore may advocate deprecated code or not follow current best practices. Caveat emptor!

Finally, if you do get into GAS and start writing lots of code, try out this color editor for your Apps Script window. It’ll change the default white screen to a dark screen with better highlight and folder options for your projects. This setup is much more akin to other professional code editors like Sublime Text.

57 thoughts on “Beginner guide to coding with Google Apps Script”

      1. Hey Ben,

        I am facing error in code for calculating distance between 2 points

        Cannot read property “legs” from undefined. (line 11, file “Code”)
        Can you please help

        1. @Rishu, were you able to fix it? I’m facing the same problem. Strangely enough it doesn’t happen all the time, script works several times and then suddenly starts giving the error. I have searched the web and it seems to be a recurring problem with no definite answer. Any help will be appreciated.

  1. Hi, Im writing some code in google script, but when I open de file, my script doesn’t work until the first minute i Think, its like there is a delay before the script really respond to my calls on buttons, do you know why is this happening?

    1. Hi Armando,

      Hmm, there shouldn’t be any substantial delay, certainly not a minute. The script could be affected by your internet connection speed, but I wouldn’t expect to see such a big delay, especially if other web services load normally.

      Inefficient code, i.e. lots of calls to/from the Google Sheets or other Google services, can make a script run slowly, so it’s best practice to minimize the number of calls required. More reading here at the official Apps Script docs:

      I suggest sharing your question/code on the Apps Script forum here: where there’s a community of experts who can suggest specific fixes.

      Hope that helps.


  2. hi, i want to track a user who copy, cut, or delete the more then 10 cells at once, please provide me a code or a way how can i do it

  3. Hi, Ben,
    Thanks for very well written article that even a beginner like myself could understand! What resources/training courses/tutorials on Google App scripts you would advise to a person that have no previous knowledge of programming.

    1. Hi Sat, there’s a list of resources at the end of this post which is where I’d start. Then try creating your own scripts and googling for answers when things don’t work. The forums are very helpful at answering specific questions.


  4. Hi, I’m french, so excuse me for my approximate English …
    I’ve tested your “Custom function/maps example” paragraph, but I’ve an error !
    When I validate the formula in spreadsheet it says: TypeError: Unable to read the “legs” property from undefined. (Line 12).

    Can you help me ??


    1. Here’s an answer I found if your still having trouble from
      This happens if the cell being referenced by the function (e.g. cell A8 in the pubic spreadsheet I provided) is made an invalid location (e.g. “XASD*&^”). So perhaps one of our locations isn’t something that Google Maps can uniquely identify as a location. Try cut/pasting it into to see how it responds.

      My script was doing the same thing until I opened up Google Maps

      1. I found that if the location is one of several that would be returned from a Maps search, an error is displayed. No real surprise there. You have to specify enough detail to make it unique. Here in the UK I was searching for ‘Dover’, but until I put ‘Dover, Kent’ the distance was not displayed.

        1. Interesting, thanks for sharing Gary. I’ve never taken this function beyond this very basic example for illustration, but clearly you could improve the error handling and give this kind of feedback to a user. Cheers!

  5. Hi Ben,

    this article is really interesting.

    I found the dashboard that connects to a Google Analytics account, pulls in social media data, checks the website status and emails really amazing and extremely useful. Do you plan to share it or to make a tutorial on how to built a dashboard like that?


  6. Very interesting. Am in dire need to learn how to develop a mobile app for e-learning/assessment. However, I don’t have knowledge of programming. I will appreciate if I can get a step by step guide on programming. Thanks. Augustine

  7. I get an error: Cannot call Browser.msgBox() from this context; have you tried Logger.log() instead? (line 2, file “Code”) when I try to run the Hello World script. Failing at the first attempt does not feel good. Do you know what the problem is?

    1. Hmm, not sure. Did you get the Authorization Required popup? What’s the exact error message you’re getting? The popup will show up in your Sheet browser tab, not the code editor tab, so you need to return to that one to the Hello World message.

      1. I did not get the authorisation pop up when I ran the script. However, i have tried it today and hit the debug icon, instead of run. This DID produce the authorisation pop up, and the function has run fine. Curious behaviour!

  8. Very useful info..

    Had one weird problem when I tried the first UI example..

    When I created the menu as you did


    var ui = SpreadsheetApp.getUi();
    ui.createMenu(‘My Custom Menu’)
    .addItem(‘Say Hello’, ‘helloWorld’)

    I got a “.createMenu undefined” error…

    didn’t shake the error message until I rewrote to

    var ui = SpreadsheetApp.getUi().createMenu(‘MyMenu’)
    .addItem(‘Hello There’, ‘helloWorld’)
    and it all worked fine.
    Have no idea what the difference is.

    I’ve had this kind of thing happen before in app script though…
    in particular when I was testing for results less than a particular variable using var1 0 and everything worked OK.

    so it’s good to teach multiple ways of doing the same thing.

  9. Hi,
    We have a container bound script and would like to password protect the Script Editor.Is there any way to do this or a workaround available to ensure that only the developer can access the Script Editor?

  10. This is awesome – Thanks!

    I’m running in to an error with the Map distance problem.
    It initially worked, and then when I tried it again with new values, it stated:
    “TypeError: Cannot read property “legs” from undefined.”

    Even when I put the old values back in, it would no longer work.

    Any suggestions?

      1. Thanks for the quick reply!

        The strange thing is that even the two points that initially worked and returned the distance, also stopped working after I tried other destinations. It only worked the first time and then everything seemed to break.

  11. What a lovely article. I’m just starting to explore all the possibilities of Google App Scripting. I don’t have any main goal yet, so I’m just fiddling around a bit.

    For starters I’d like to know whatever is possible with an app inside a google site, and I didn’t find any documentation on how to implement custom UI controls on the properties on the embedded app.
    To clarify: I add a script in my google site, then on a page I add a “Google Script App”, and add that script I just made. Then for that added ‘widget’, you can click on the edit button. I’d like to know how to add my custom settings on that page.

    I know it’s possible, as other existing widgets can do this too.

    Any help on this one?

  12. I am new to scripting. I have 12 functions in a single script. I cannot find a suitable answer to this question:

    How can I link my scripts so that all 12 run sequentially?

    Thank you very much!

    1. Hey Brian,

      I can understand your frustration, I was there once too 🙂

      You can call your 12 functions inside another, sort of master execution function, if you will, like this:

      function runFuncs() {
      // put your 12 functions in here...
      // etc...

      function func1() {

      function func2() {

      where func1 and func2 would be the first two of your 12 functions. When you run runFuncs(), it will execute those functions inside of it, func1 and func2 in this case, but could be all your 12.

      Hope that helps!


  13. I am a new user to google sheets and I love working with excel automation and advance excel. I searched about google sheet programming, and your this article become very beneficial to me.

    Great work!

  14. Hey Ben, I have a real beginner’s question.
    How do I get the “suggestion screen” on screen when I’m typing code. I have a Chromebook.

    Thanks for your answer.

  15. Hi Ben, I am using getcharts() to retrieve and save a manually produced chart in google sheets. I keep getting a google server error ‘We’re sorry, a server error occurred. Please wait a bit and try again. (line 4, file “Code”)’. The code is below – can you please help me with what I am doing wrong? Is it because the chart was not created with GAS in the first place?
    function myFunction()
    { var spreadsheet1=SpreadsheetApp.getActive();
    var sheet = spreadsheet1.getSheets()[0]; // grabs active sheet
    var chartvarun = sheet.getCharts(); // grabs the first chart on the sheet
    var file = DriveApp.createFile(chart.getBlob()); // saves it as a file

    1. @Varun – were you able to solve this? I am getting the same error. Strangely, I am using the identical code on two sheets and only get an error on one.

  16. Hi Ben,

    I am a junior programmer and my company has asked me to do some google docs work that I have never touched before. Since we are a small company I would love to hear your input…
    Can you advise how I would export cvs data from an excel sheet/url to a google doc? I need it automated to occur once a week.


  17. I have search for a language refernece card for keywords, srtuctures and I could not find yet but some fragments. Any idea where I could find a refcard, a cheat card, thank you

  18. Hello i tried to code the example but i keep gettign this error:

    Cannot call Browser.msgBox() from this context; have you tried Logger.log() instead? (line 2, file “Code”)
    function myFunction() {

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