Ampersand documentation

Ampersand executes AMPscript entirely in your browser and shows the rendered email instantly - no Salesforce Marketing Cloud account, no server, no publish cycle. Templates, subscriber data, and data extensions never leave your machine.

Quick start

Template tab: write HTML + AMPscript; the preview re-renders on every keystroke.
Subscriber Data tab: a JSON object of attributes. %%FirstName%%, [FirstName], and bare identifiers in expressions all read from it, case-insensitively.
Data Extensions tab: one CSV per === Name === section; the first row is the header. Lookup functions read these; Insert/Update/Upsert/DeleteDE write to them for the current render only.
Content Blocks tab: one block per === Name === section, resolved by ContentBlockByName/Key/Id. AMPscript inside blocks executes.

Supported syntax

%%[ ... ]%% code blocks and <script runat="server" language="ampscript"> blocks
%%=Expression=%% inline output
Personalization strings: %%Attribute%% and [Attribute]
VAR, SET, IF / ELSEIF / ELSE / ENDIF, FOR ... TO / DOWNTO ... NEXT, AND / OR / NOT, comparisons, comments
Control flow spanning blocks: %%[ IF ... THEN ]%% html %%[ ENDIF ]%%
Case-insensitive keywords, functions, variables, and string comparison

Function reference (83 functions)

String

`Concat(str1, str2, ...)`	Null arguments become empty strings
`Length(str)`
`Lowercase(str)`
`Uppercase(str)`
`ProperCase(str)`	Capitalizes the first letter of each word
`Trim(str)`
`Replace(str, find, replaceWith)`	Case-sensitive
`ReplaceList(str, replaceWith, find1, [find2, ...])`
`IndexOf(str, search)`	1-based; returns 0 when not found; case-insensitive
`Char(charCode, [repeatCount])`
`Substring(str, start, [length])`	1-based start
`RegExMatch(str, pattern, group, [options...])`	Group by number or name; supports IgnoreCase / Multiline options
`BuildRowsetFromString(str, delimiter)`	Access parts with Row() + Field(row, 1)
`StringToDate(str)`
`StringToHex(str)`	UTF-8 bytes as hex

Math

`Add(a, b)`
`Subtract(a, b)`
`Multiply(a, b)`
`Divide(a, b)`	Division by zero is a render error
`Mod(a, b)`
`Random(min, max)`	Integer, inclusive

Date & time

`Now()`	Your local machine time
`GetSendTime()`	Same as Now() locally
`DateParse(str, [utc])`
`DateAdd(date, amount, unit)`	Units: Y, M, D, H, MI
`DateDiff(start, end, unit)`	Units: Y, M, D, H, MI
`DatePart(date, part)`	year, month, monthName, day, hour, minute; month and day are zero-padded like SFMC
`Format(value, pattern, [type], [culture])`	.NET-style date and number patterns (yyyy, MMMM, N2, C2, ...)
`FormatDate(date, datePattern, [timePattern], [culture])`
`FormatNumber(number, pattern, [culture])`	N/C/P/F patterns and #,##0.00-style masks; en-US output
`LocalDateToSystemDate(date)`	Approximation: SFMC system time modeled as CST (UTC-6, no DST)
`SystemDateToLocalDate(date)`	Same approximation as above

Utility

`V(value)`
`IIF(condition, ifTrue, ifFalse)`	Both branches are evaluated
`Empty(value)`	True for null or empty string
`IsNull(value)`
`IsNullDefault(value, default)`
`AttributeValue(name)`	Reads from the Subscriber Data tab; null when missing
`Output(value)`	Writes into the output stream from inside a code block
`OutputLine(value)`	Output() plus a newline
`RaiseError(message, [skipSend])`	Stops the whole render, like it stops a send
`UrlEncode(str, [spacesAsPlus], [encodeAll])`
`RedirectTo(url)`	Returns the URL (no link-tracking wrap locally)
`GUID()`
`WrapLongURL(url)`	Identity locally
`IsEmailAddress(str)`
`IsPhoneNumber(str)`	North American 10/11-digit check

Data extensions

Data extensions come from the Data Extensions tab (one CSV per "=== Name ===" section; first row is the header). Writes mutate the in-memory copy for the current render only - every render starts fresh from your CSV, so previews stay deterministic.

`Lookup(de, returnCol, col, value, [col2, value2, ...])`	First match; null when no match (IsNull is True), matching SFMC
`LookupRows(de, col, value, ...)`	Case-insensitive match
`LookupRowsCS(de, col, value, ...)`	Case-sensitive match
`LookupOrderedRows(de, count, "field asc\|desc", col, value, ...)`	count <= 0 returns all matches
`LookupOrderedRowsCS(de, count, "field asc\|desc", col, value, ...)`
`DataExtensionRowCount(de)`
`RowCount(rowset)`
`Row(rowset, index)`	1-based
`Field(row, nameOrOrdinal, [raiseError])`	Ordinal is 1-based
`InsertDE(de, col, value, ...)`
`InsertData(de, col, value, ...)`	Returns rows affected
`UpdateDE(de, numKeys, keyCol, keyVal, ..., col, value, ...)`
`UpdateData(de, numKeys, keyCol, keyVal, ..., col, value, ...)`	Returns rows affected
`UpsertDE(de, numKeys, keyCol, keyVal, ..., col, value, ...)`
`UpsertData(de, numKeys, keyCol, keyVal, ..., col, value, ...)`	Returns rows affected
`DeleteDE(de, numKeys, keyCol, keyVal, ...)`
`DeleteData(de, numKeys, keyCol, keyVal, ...)`	Returns rows deleted

Content

Content blocks come from the Content Blocks tab (one block per "=== Name ===" section, matched by name, key, or id). AMPscript inside included content executes, just like in SFMC.

`ContentBlockByName(name, [region], [raiseError], [default])`
`ContentBlockByKey(key, [region], [raiseError], [default])`
`ContentBlockById(id, [region], [raiseError], [default])`
`ContentArea(id, [region], [raiseError], [default])`
`ContentAreaByName(name, [region], [raiseError], [default])`
`TreatAsContent(str)`	Executes the string as AMPscript content
`BeginImpressionRegion([name])`	No-op locally
`EndImpressionRegion()`	No-op locally
`ContentImageById(id, [defaultUrl])`	Resolves from Content Blocks; falls back to a placeholder image
`ContentImageByKey(key, [defaultUrl])`	Same fallback behavior
`TransformXML(xml, xslt)`	Uses the browser XSLT engine; browser preview only

Encryption & encoding

`MD5(str, [charset])`	Lowercase hex
`SHA1(str, [charset])`
`SHA256(str, [charset])`
`SHA512(str, [charset])`
`Base64Encode(str, [charset])`	UTF-8
`Base64Decode(str, [charset])`
`EncryptSymmetric(value, cipher, pwdKeyName, password, [saltKeyName, salt, ivKeyName, iv])`	AES-CBC; round-trips locally, but ciphertext will not byte-match SFMC (different key derivation)
`DecryptSymmetric(value, cipher, pwdKeyName, password, [saltKeyName, salt, ivKeyName, iv])`

Not supported: platform-only functions

These require a live Marketing Cloud org and can never run locally. Calling one produces a clear error naming its category.

Marketing Cloud API	Addobjectarrayitem, Createobject, Invokecreate, Invokedelete, Invokeexecute, Invokeperform, Invokeretrieve, Invokeupdate, Setobjectproperty, Executefilter, Executefilterorderedrows
Sales & Service Cloud	Createsalesforceobject, Updatesinglesalesforceobject, Retrievesalesforceobjects, Retrievesalesforcejobsources, Longsfid
HTTP (mock support planned)	Httpget, Httppost, Httppost2, Httprequestheader, Ischtmlbrowser
CloudPages / Microsites (mock support planned)	Cloudpagesurl, Micrositeurl, Livecontentmicrositeurl, Queryparameter, Requestparameter, Redirect
Contact Model	Upsertcontact
Einstein	Einsteinemailrecommendations
MobileConnect (SMS)	Createsmsconversation, Endsmsconversation, Setsmsconversationnextkeyword
Social	Getsocialpublishurl, Getsocialpublishurlbyname, Getpublishedsocialcontent
Microsoft Dynamics CRM	Createmscrmrecord, Describemscrmentities, Describemscrmentityattributes, Retrievemscrmrecords, Retrievemscrmrecordsfetchxml, Setstatemscrmrecord, Updatemscrmrecords, Upsertmscrmrecord
Key Management	Getjwt, Getjwtbykeyname
Content (platform assets)	Barcodeurl, Image, Getportfolioitem, Attachfile

Limitations and approximations

SSJS and GTL are not executed - they pass through as literal text (roadmap).
System strings (jobid, listid, ...) are not built in - define them in Subscriber Data.
EncryptSymmetric/DecryptSymmetric round-trip locally but use a local key derivation, so ciphertext will not byte-match SFMC output.
System-time conversions model SFMC server time as CST (UTC-6) without DST.
Client-compatibility findings are powered by the caniemail dataset - static checks on the rendered HTML, not pixel-accurate client rendering.

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