What is a JSON array?
Quick answer
A JSON array is an ordered list written inside square brackets, with entries separated by commas, such as ["Tax", "Payroll"]. Often each entry is an object with its own fields, for example a list of tasks where each has a task, an owner and a due day. Automations usually split an array so each entry becomes its own row or item.
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Updated · By Robert Breen
Why it matters for a small business
Lists are everywhere in business data: the line items on an invoice, the attachments on an email, the action items from a meeting. Apps and AI models send those lists as JSON arrays. If you map the whole array into one spreadsheet cell, you get an unreadable blob; if you split it, you get one clean row per entry.
Asking an AI for an array is also a reliable way to get usable output. "Return a list called tasks, each with task, owner and due" gives you something a workflow can split and write to a sheet, instead of a paragraph someone has to retype.
Where you'll use it: in n8n's output panel, switch to the JSON view and look for square brackets. The Split Out node turns an array into separate items. In Make, an iterator does the same, and in Zapier, line-item fields handle lists.
In a real lesson: n8n: Turn Meeting Notes into Action Items in a Google Sheet
In the free n8n Meeting Notes to Action Items lesson, Meridian Accounting Group (made up) reads two meetings from a Google Sheet. The OpenAI prompt asks for JSON in a fixed shape: a list called tasks, each with a task, an owner and a due day, and you set the response format to JSON Object.
The output shows 2 items, one per meeting, each holding a tasks array: 4 tasks for the first meeting and 3 for the second. A Split Out node on the tasks field turns those arrays into 7 separate items, and each becomes a row in the Action Items sheet.
Try this lesson free or read the step-by-step guide.
Common confusions
JSON array vs JSON object
An array is a list in square brackets. An object is a set of named fields in curly braces. Arrays often hold objects.
Array vs n8n items
n8n passes data between nodes as a list of items. An array can sit inside one item until you split it out.
Tips
- Name the array in your AI prompt, such as tasks, so you know which field to split.
- Check that every entry has the same fields before writing to a sheet.
- An empty array, [], is valid and means "no entries", so plan for it.
Related terms
More Data, Sheets and Gmail terms
Where you use it: free lessons
- n8n: Turn Meeting Notes into Action Items in a Google Sheet (n8n, 15 min)
- n8n: Items, JSON and Expressions, Explained by Doing (n8n, 9 min)
- Meeting to Action: Recap, Tracker Rows and a Kickoff Deck (ChatGPT, n8n, Gamma) (n8n, 14 min)
Frequently asked questions
- How do I write a JSON array into Google Sheets?
- Split it first, so each entry is its own item, then use an append row step. Each item becomes one row.
- Can a JSON array hold different kinds of values?
- Yes, but for automations it is far easier when every entry has the same shape.