class Utilities method .base64Decode()

Utilities is the Apps Script service.

.base64Decode() is the method name you will see after a dot in your code.

What it does

Decodes a Base64 string back into raw data.

Why it's used

  • Read Base64 attachments or API fields back into raw data.
  • Reverse encoding from external systems.

Common errors

  • Forgetting parentheses on base64Decode. Write Utilities.base64Decode(), not Utilities.base64Decode or base64Decode by itself.
  • Skipping dots between chained calls. Each step needs a dot, like Utilities.base64Decode().
  • Adding spaces where they do not belong. Write Utilities.base64Decode(), not Utilities .base64Decode(), Utilities.base64Decode (), or Utilities . base64Decode().
  • Wrong capitalization. Use Utilities and base64Decode, not utilities or base64decode.

Explore

Related methods

Better Sheets tutorials

Password Protecting Data In a Google Sheet

Password Protecting Data In a Google Sheet

A funky way to password protect some data in a sheet, 3 ways to do it: w...
Password Protecting Data In a Google Sheet Part 2 The Basics

Password Protecting Data In a Google Sheet Part 2 The Basics

Covering some of the basics I skipped over in the part 1 video.

Related blog posts

Written guides about Utilities.base64Decode().

Browse the blog
Big Year 2027 calendar: the whole year on one Google Sheet

Free 2027 calendar.Plan all of 2027 on one Google Sheet, free.

Copy it to your Google Drive.

Free. No password, no card. The sheet link shows up right here.