Trigger Types in Google Apps Script Explained

Triggers are what make Apps Script truly powerful — they let your code run automatically in response to events, without anyone clicking a button. Here's a complete guide to all trigger types.

Simple triggers

Simple triggers are built-in functions that Apps Script recognises by name and runs automatically. No setup required — just define the function.

// Runs when the spreadsheet is opened
function onOpen(e) {
  SpreadsheetApp.getUi()
    .createMenu('Custom Menu')
    .addItem('Run Report', 'runReport')
    .addToUi();
}

// Runs when a cell is edited
function onEdit(e) {
  const range = e.range;
  Logger.log(`Edited: ${range.getA1Notation()} = ${range.getValue()}`);
}

// Runs when the spreadsheet is changed (including programmatic changes)
function onChange(e) {
  Logger.log('Change type: ' + e.changeType);
}

// Runs when a form is submitted (from a bound form)
function onFormSubmit(e) {
  Logger.log('Form submitted: ' + JSON.stringify(e.namedValues));
}

Limitations of simple triggers

Cannot perform actions that require authorisation (send email, access Drive, call external APIs).
Always run as the user who performed the action.
Cannot be used in standalone scripts (only container-bound).

Installable triggers

Installable triggers overcome simple trigger limitations. They run with the script owner's authorisation and can perform any action.

Create programmatically

function createInstallableOnEdit() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  ScriptApp.newTrigger('onEditInstallable')
    .forSpreadsheet(ss)
    .onEdit()
    .create();
}

function onEditInstallable(e) {
  // Can now send emails, access Drive, etc.
  if (e.range.getColumn() === 5 && e.value === 'Done') {
    GmailApp.sendEmail('[email protected]', 'Task completed', `Row ${e.range.getRow()} marked done.`);
  }
}

Create via the UI

Open the script editor.
Click the Triggers icon (clock) in the left sidebar.
Click + Add Trigger.
Configure the function, event source, and event type.

Time-based triggers

Run code on a schedule — every minute, hourly, daily, or weekly.

function createTimeTriggers() {
  // Every 5 minutes
  ScriptApp.newTrigger('checkAlerts')
    .timeBased()
    .everyMinutes(5)
    .create();

  // Every hour
  ScriptApp.newTrigger('syncData')
    .timeBased()
    .everyHours(1)
    .create();

  // Every day at 8 AM
  ScriptApp.newTrigger('sendDailyReport')
    .timeBased()
    .everyDays(1)
    .atHour(8)
    .create();

  // Every Monday at 9 AM
  ScriptApp.newTrigger('sendWeeklyReport')
    .timeBased()
    .onWeekDay(ScriptApp.WeekDay.MONDAY)
    .atHour(9)
    .create();

  // First of every month at 7 AM
  ScriptApp.newTrigger('monthlyReport')
    .timeBased()
    .onMonthDay(1)
    .atHour(7)
    .create();
}

Form submit triggers

function createFormTrigger() {
  const form = FormApp.openById('YOUR_FORM_ID');
  ScriptApp.newTrigger('handleFormSubmit')
    .forForm(form)
    .onFormSubmit()
    .create();
}

function handleFormSubmit(e) {
  const email = e.response.getRespondentEmail();
  Logger.log('New submission from: ' + email);
}

Calendar triggers

function createCalendarTrigger() {
  ScriptApp.newTrigger('onCalendarUpdated')
    .forUserCalendar(Session.getActiveUser().getEmail())
    .onEventUpdated()
    .create();
}

function onCalendarUpdated(e) {
  Logger.log('Calendar updated: ' + e.calendarId);
}

List and delete triggers

function listAllTriggers() {
  const triggers = ScriptApp.getProjectTriggers();
  triggers.forEach(t => {
    Logger.log(`Function: ${t.getHandlerFunction()} | Type: ${t.getEventType()} | Source: ${t.getTriggerSource()}`);
  });
}

function deleteAllTriggers() {
  ScriptApp.getProjectTriggers().forEach(t => ScriptApp.deleteTrigger(t));
  Logger.log('All triggers deleted.');
}

function deleteTriggerByFunction(fnName) {
  ScriptApp.getProjectTriggers()
    .filter(t => t.getHandlerFunction() === fnName)
    .forEach(t => ScriptApp.deleteTrigger(t));
}

Comparison summary

Type	Auth required	Min interval	Use case
Simple `onEdit`	No	Instant	Basic UI reactions
Installable `onEdit`	Yes	Instant	Edits that need email/Drive
Time-based	Yes	1 minute	Scheduled jobs
Form submit	Yes	Instant	Workflow on form response
Calendar	Yes	Instant	React to calendar changes

Tips

Run trigger setup functions once — check for duplicates before creating to avoid multiple triggers on the same function.
Each trigger counts toward your daily trigger quota. Keep the number of triggers per project low.
Enable failure notifications in the trigger settings so you're alerted when a trigger execution fails.