Power Automate Expressions Cheat Sheet (2026)

Why You Need This Cheat Sheet

Power Automate expressions are the difference between a basic flow and one that actually handles real-world data. Without them, you are stuck with static values and rigid logic. With them, you can parse dates, manipulate strings, handle nulls, and build dynamic content on the fly.

You write expressions in the expression editor -- click any input field in your flow, select the "Expression" tab, type your function, and hit OK. Every expression starts with a function name and returns a value that gets inserted into that field.

This cheat sheet covers every function you are likely to need, organized by category with copy-paste examples.

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String Functions

Function	Syntax	Example	Output
concat	concat(text1, text2, ...)	concat('Hello', ' ', 'World')	Hello World
substring	substring(text, startIndex, length)	substring('PowerAutomate', 5, 8)	Automate
replace	replace(text, oldText, newText)	replace('Hello World', 'World', 'Flow')	Hello Flow
split	split(text, delimiter)	split('a;b;c', ';')	["a","b","c"]
toLower	toLower(text)	toLower('HELLO')	hello
toUpper	toUpper(text)	toUpper('hello')	HELLO
trim	trim(text)	trim(' hello ')	hello
indexOf	indexOf(text, searchText)	indexOf('Hello World', 'World')	6
length	length(text)	length('Power')	5
startsWith	startsWith(text, searchText)	startsWith('PowerAutomate', 'Power')	true
endsWith	endsWith(text, searchText)	endsWith('report.pdf', '.pdf')	true
contains	contains(text, searchText)	contains('Hello World', 'World')	true
formatNumber	formatNumber(number, format)	formatNumber(1234.5, 'C2')	$1,234.50

String Tips

Use concat() instead of the @{...} inline syntax when you need to combine more than two dynamic values -- it is easier to debug. When checking user input, always wrap the value in toLower() or toUpper() first so your comparisons are case-insensitive.

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Date and Time Functions

Function	Syntax	Example	Output
utcNow	utcNow(format?)	utcNow('yyyy-MM-dd')	2026-04-03
addDays	addDays(timestamp, days, format?)	addDays(utcNow(), 7, 'yyyy-MM-dd')	7 days from now
addHours	addHours(timestamp, hours, format?)	addHours(utcNow(), -3)	3 hours ago
addMinutes	addMinutes(timestamp, minutes)	addMinutes(utcNow(), 30)	30 min from now
formatDateTime	formatDateTime(timestamp, format)	formatDateTime(utcNow(), 'MM/dd/yyyy')	04/03/2026
convertTimeZone	convertTimeZone(timestamp, source, dest, format?)	convertTimeZone(utcNow(), 'UTC', 'Eastern Standard Time', 'hh:mm tt')	08:30 AM
dayOfWeek	dayOfWeek(timestamp)	dayOfWeek('2026-04-03')	5 (Friday)
dayOfMonth	dayOfMonth(timestamp)	dayOfMonth('2026-04-03')	3
ticks	ticks(timestamp)	ticks('2026-01-01')	Tick count
dateDifference	dateDifference(startDate, endDate)	dateDifference('2026-01-01', '2026-04-03')	92.00:00:00

Date Tips

The formatDateTime() function uses .NET custom date format strings. Common patterns: yyyy-MM-dd for ISO, MM/dd/yyyy for US, dd/MM/yyyy for EU, and dddd, MMMM d, yyyy for display (e.g., "Friday, April 3, 2026"). Always convert to the user's time zone with convertTimeZone() before displaying dates in emails.

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Collection and Array Functions

Function	Syntax	Example	Output
first	first(collection)	first(createArray('a','b','c'))	a
last	last(collection)	last(createArray('a','b','c'))	c
length	length(collection)	length(createArray('a','b','c'))	3
contains	contains(collection, value)	contains(createArray('a','b'), 'b')	true
join	join(collection, delimiter)	join(createArray('a','b','c'), '; ')	a; b; c
split	split(text, delimiter)	split('a,b,c', ',')	["a","b","c"]
union	union(collection1, collection2)	union(createArray(1,2), createArray(2,3))	[1,2,3]
intersection	intersection(col1, col2)	intersection(createArray(1,2,3), createArray(2,3,4))	[2,3]
skip	skip(collection, count)	skip(createArray('a','b','c'), 1)	["b","c"]
take	take(collection, count)	take(createArray('a','b','c'), 2)	["a","b"]
createArray	createArray(item1, item2, ...)	createArray(1, 2, 3)	[1,2,3]

Array Tips

Use empty() to check if an array has items before looping. Combine skip() and take() for pagination. The union() function also works to merge two objects (not just arrays), which is useful for building dynamic JSON payloads.

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Logical Functions

Function	Syntax	Example	Output
if	if(expression, valueIfTrue, valueIfFalse)	if(equals(1,1), 'yes', 'no')	yes
equals	equals(value1, value2)	equals(toLower('Hello'), 'hello')	true
and	and(expr1, expr2)	and(greater(5,3), less(5,10))	true
or	or(expr1, expr2)	or(equals(1,2), equals(1,1))	true
not	not(expression)	not(equals(1,2))	true
greater	greater(value1, value2)	greater(10, 5)	true
greaterOrEquals	greaterOrEquals(value1, value2)	greaterOrEquals(5, 5)	true
less	less(value1, value2)	less(3, 5)	true
lessOrEquals	lessOrEquals(value1, value2)	lessOrEquals(5, 5)	true
empty	empty(value)	empty('')	true
coalesce	coalesce(value1, value2, ...)	coalesce(null, null, 'default')	default

Logic Tips

You cannot nest if() more than a few levels deep before it becomes unreadable. If you need complex branching, use a Condition or Switch action instead. The coalesce() function is your best friend for handling null values from SharePoint or Dataverse -- it returns the first non-null value in the list.

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Conversion Functions

Function	Syntax	Example	Output
int	int(value)	int('42')	42
float	float(value)	float('3.14')	3.14
string	string(value)	string(42)	"42"
bool	bool(value)	bool(1)	true
json	json(value)	json('{"name":"test"}')	JSON object
xml	xml(value)	xml('1')	XML object
base64	base64(value)	base64('Hello')	SGVsbG8=
base64ToString	base64ToString(value)	base64ToString('SGVsbG8=')	Hello
decodeBase64	decodeBase64(value)	decodeBase64('SGVsbG8=')	Hello
uriComponent	uriComponent(value)	uriComponent('hello world')	hello%20world
decodeUriComponent	decodeUriComponent(value)	decodeUriComponent('hello%20world')	hello world

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Common Patterns

These are the expressions you will copy-paste most often in production flows.

Format a Date as MM/dd/yyyy

When SharePoint returns an ISO timestamp and you need a clean date for an email:

formatDateTime(triggerOutputs()?['body/Created'], 'MM/dd/yyyy')

For a friendly format like "April 3, 2026":

formatDateTime(triggerOutputs()?['body/Created'], 'MMMM d, yyyy')

Get File Extension from a Filename

Extract the extension from a file name dynamic value:

last(split(triggerOutputs()?['body/{FilenameWithExtension}'], '.'))

This splits report-final.pdf by the dot and returns pdf.

Null-Safe Field Access

SharePoint People columns and lookup columns return null when empty. Wrap them with coalesce() to avoid flow failures:

coalesce(triggerOutputs()?['body/Manager/Email'], 'no-manager@contoso.com')

For numeric fields that might be null:

coalesce(triggerOutputs()?['body/Amount'], 0)

Build a Dynamic Email Subject

Combine multiple fields into a subject line for approval emails:

concat('[', triggerOutputs()?['body/Department'], '] ', triggerOutputs()?['body/RequestType'], ' - ', triggerOutputs()?['body/Title'])

Output: [Finance] Purchase Order - Office Supplies Q2

For more on building approval flows, see the full guide at Power Automate Document Approval Workflow.

Calculate Business Days Between Two Dates

There is no built-in business days function. Use dateDifference() to get total days, then account for weekends with this approach:

div(mul(div(sub(ticks(outputs('EndDate')), ticks(outputs('StartDate'))), 864000000000), 5), 7)

This calculates a rough estimate. For exact results accounting for holidays, store holiday dates in a SharePoint list and loop through them.

Parse JSON from an HTTP Response

When calling an external API with the HTTP action, parse the response body:

json(body('HTTP_Request'))?['results']

To safely access a nested property:

coalesce(json(body('HTTP_Request'))?['data']?['value'], 'Not found')

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Quick Reference: Expression Editor Shortcuts

A few things that trip up new users:

• Accessing dynamic content in expressions: Use triggerOutputs(), outputs('ActionName'), or body('ActionName') to reference values.

• Optional chaining: The ? operator (e.g., body('Get_item')?['value']) prevents errors when a property does not exist.

• Nested quotes: Use single quotes inside expressions. Double quotes break the parser.

• Testing expressions: Use a Compose action to test any expression -- the output shows exactly what it returns.

For styled HTML output in your flow emails, check out Power Automate HTML Table Styling with CSS. You can also try our interactive Power Automate Expressions Tool to test functions directly in the browser. These same expression patterns are equally powerful in Power Apps canvas formulas — see our guide on Power Apps canvas apps and SharePoint integration for examples of expressions in action.

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Expression Syntax Deep Dive

Understanding how Power Automate parses expressions prevents the majority of "InvalidTemplate" errors you will hit in production.

The Two Syntaxes

Power Automate has two ways to embed expressions in an action's input field:

Syntax	When to Use	Example
Dynamic content tab	Simple field references with no transformation	Picking a trigger field from the picker
@{expression} inline	Embedding an expression inside a larger string	Hello @{triggerOutputs()?['body/Title']}
Expression tab (pure mode)	Returning a single computed value	concat('Ref-', string(triggerOutputs()?['body/ID']))

The key rule: if the entire field value is one expression, use the Expression tab and do not wrap it in @{}. If you are embedding inside a string (e.g., an email body), use the inline @{...} syntax.

Accessing Outputs Correctly

There are three accessor patterns you will use constantly:

triggerOutputs()?['body/FieldName']        # trigger (manual, SharePoint, etc.)
outputs('Action_Name')?['body/FieldName']  # generic action output
body('Action_Name')?['FieldName']          # shorthand for body of a specific action

The ? before ['...'] is the null-safe operator. Without it, your flow throws a runtime error the first time a field is missing. Always use it unless you have a hard guarantee the property exists.

Operator Precedence and Parentheses

Power Automate does not have infix operators (+, >, etc.) in expressions — everything is a function call. To check "is A greater than B and less than C":

and(greater(variables('Score'), 60), less(variables('Score'), 100))

This functional style means you never get operator precedence surprises. When logic gets deeply nested, extract intermediate values into Compose actions and reference them with outputs('Compose') — far easier to debug than a 200-character nested expression.

Type-Safety Gotchas

• SharePoint Number columns return a string when accessed via trigger outputs in some connectors — always wrap with int() or float() before arithmetic.

• Boolean columns from SharePoint return true/false as proper booleans in the trigger body. Use equals(triggerOutputs()?['body/IsApproved'], true), not equals(..., 'true').

• Dataverse columns follow OData types: DateTime comes as ISO 8601 UTC, so formatDateTime() works directly without a conversion step.

For the full function reference, see Microsoft's Workflow Definition Language functions reference — Power Automate and Logic Apps share the same expression engine.

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SharePoint-Specific Expression Patterns

SharePoint is the most common data source for Power Automate flows. These patterns cover the field types that trip up developers at least once.

People Picker (Person or Group column)

A People column returns an object, not a string. To get the email address:

triggerOutputs()?['body/AssignedTo/Email']

For a multi-select People field it returns an array of objects. To get the first person's email:

first(triggerOutputs()?['body/AssignedTo'])?['Email']

Choice Columns

A single-select Choice column returns the display value as a plain string — no unwrapping needed:

triggerOutputs()?['body/Status']

A multi-select Choice column returns an array of { "Value": "..." } objects. To join them into a comma-separated string you need a Select action first to extract just the Value property, then:

join(body('Select_Choice_Values'), ', ')

Lookup Columns

A Lookup column returns an object with Id and Value:

triggerOutputs()?['body/Department/Value']   # display text
triggerOutputs()?['body/Department/Id']      # numeric lookup ID

Managed Metadata (Taxonomy)

Managed Metadata fields return a { "Label": "...", "TermGuid": "...", "WssId": "..." } object. To get just the tag label:

triggerOutputs()?['body/TaxonomyField/Label']

SharePoint Column Expression Quick Reference

Column Type	Access Pattern	Common Mistake
Text / Number	?['body/FieldName']	Forgetting ? null-safe operator
People (single)	?['body/Field/Email']	Treating it as a plain string
People (multi)	first(...)?['Email'] or Select + join	Joining objects instead of values
Choice (single)	?['body/Field']	None — works as-is
Choice (multi)	Select action + join()	Joining object array directly
Lookup	?['body/Field/Value']	Forgetting /Value sub-property
Date	formatDateTime(..., 'MM/dd/yyyy')	Displaying raw UTC to users
Managed Metadata	?['body/Field/Label']	Forgetting /Label sub-property

For a deep dive into SharePoint permissions and how they surface in flow triggers, see the SharePoint Online Permissions Complete Guide. To automate SharePoint provisioning with these same expression patterns, check the SharePoint Provisioning Automation Guide.

Official references:

• Power Automate documentation — connector-specific output schemas

• SharePoint connector for Power Automate — exact field output shapes per trigger and action

• Workflow Definition Language functions reference — every expression function with full parameter types

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FAQ

What is the difference between concat() and formatString()?

concat() joins values end-to-end: concat('Hello', ' ', 'World') returns Hello World. You can pass any number of arguments. There is no separate formatString() in Power Automate -- use concat() for all string building, or use inline expressions with @{...} syntax directly in action inputs for simpler cases.

Can you nest expressions inside other expressions?

Yes, and you will do this constantly. For example, if(empty(triggerOutputs()?['body/Email']), 'N/A', toLower(triggerOutputs()?['body/Email'])) checks if a field is empty before transforming it. Just be careful with parentheses -- one missing closing paren and the whole expression fails with a cryptic error.

How do you handle time zones in Power Automate?

Always use convertTimeZone() before displaying dates to users. Power Automate stores all timestamps in UTC internally. The function takes the timestamp, source zone (usually 'UTC'), destination zone (e.g., 'Eastern Standard Time'), and an optional format string. You can find the full list of supported time zone names in the Microsoft documentation.

Why does my expression return an error about "InvalidTemplate"?

This usually means one of three things: a syntax error (check your parentheses and single quotes), a type mismatch (you are passing a string where a number is expected -- use int() or float() to convert), or a null reference (the dynamic content you are referencing does not exist at runtime -- wrap it in coalesce()).