7 n8n expression tricks that will save you hours

n8n expressions are powerful but the docs don't cover everything. Here are patterns we use constantly.

1. Safe property access

Don't let missing data crash your workflow:

// Bad - crashes if customer or address is undefined
{{ $json.customer.address.city }}

// Good - returns undefined safely
{{ $json.customer?.address?.city }}

// Better - provide a default
{{ $json.customer?.address?.city ?? 'Unknown' }}

2. Transform arrays in one expression

Need to extract a field from every item in an array?

// Get all email addresses from a list of contacts
{{ $json.contacts.map(c => c.email) }}

// Filter and map together
{{ $json.items.filter(i => i.active).map(i => i.name) }}

3. Conditional text without IF nodes

Sometimes you need different text based on a condition:

// Ternary for simple cases
{{ $json.status === 'vip' ? 'Priority support' : 'Standard support' }}

// Template literals for complex messages
{{ `Hello ${$json.name}, your ${$json.items.length} items are ready.` }}

4. Date formatting without a Code node

n8n uses Luxon for dates:

// Current timestamp
{{ $now.toISO() }}

// Format a date field
{{ DateTime.fromISO($json.created_at).toFormat('MMM d, yyyy') }}
// Output: "Dec 27, 2025"

// Relative time
{{ DateTime.fromISO($json.created_at).toRelative() }}
// Output: "2 days ago"

5. Access data from other nodes

You're not limited to the previous node:

// Get data from a specific node
{{ $('HTTP Request').item.json.id }}

// Get all items from a node (useful after splits)
{{ $('Get Users').all().map(i => i.json.email) }}

// First item only
{{ $('Webhook').first().json.body }}

6. Clean up strings

// Trim whitespace
{{ $json.name.trim() }}

// Lowercase for comparison
{{ $json.email.toLowerCase() }}

// Extract domain from email
{{ $json.email.split('@')[1] }}

// Remove special characters
{{ $json.input.replace(/[^a-zA-Z0-9]/g, '') }}

7. Work with numbers

// Round to 2 decimal places
{{ Math.round($json.price * 100) / 100 }}

// Sum an array of numbers
{{ $json.items.reduce((sum, i) => sum + i.amount, 0) }}

// Format as currency (simple version)
{{ '$' + $json.total.toFixed(2) }}

Bonus: Debug expressions

When an expression isn't working, wrap it to see what's happening:

// See the actual value
{{ JSON.stringify($json.mystery_field) }}

// Check the type
{{ typeof $json.field }}

// See all available fields
{{ Object.keys($json) }}

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These patterns come up in almost every project. Save yourself the debugging time.