Formula Coverage

This page explains which Excel function names Formulon recognizes and which of them execute locally. Internally, it reflects the runtime registry report from RegistryCatalog.CoverageReport and the availability annotations in tools/catalog/function_status.tsv.

Recognized does not mean locally executable

The 526-function number is the count of Excel function names Formulon recognizes. It includes names that Excel routes to external services or host-specific state, such as COPILOT, PY, IMAGE, RTD, STOCKHISTORY, WEBSERVICE, translation functions, and CUBE connection functions. Those are recognized deliberately, but they are not local implementations.

Summary

Formulon recognizes 526 Excel function names: 511 real implementations, including 2 environment-bound (CELL, INFO), plus 15 unavailable stubs.

Status	Count	Meaning
Real implementation	511	Evaluated locally; 2 (CELL, INFO) depend on workbook or host state
Unavailable service stub	15	Recognized by name and arity, but returns a deterministic Excel error because the required external service is outside Formulon
Total recognized	526

Recognizing a function name does not mean Formulon runs it locally: 15 names need an external service.

Formulon evaluates almost every recognized function locally, but it does not embed Microsoft 365 cloud services, a Python cloud runtime, an HTTP client, an OLAP cube connection, an RTD COM provider, or Copilot.

The panel below reads the same registry at runtime: functionNames() for the index and functionMetadata(name) for canonical name, arity, and availability class. Its counts come from the engine, not from this page. Its try-it field evaluates a call, so you can see what a recognized-but-unavailable name returns. Function metadata is locale-invariant and carries no human-readable signatures or descriptions; a host can merge its own localized help catalog on top.

Look up the function catalog

The index and every count come from the running engine’s functionNames() / functionMetadata(); this page carries no function table of its own.

Powered by the real Formulon engine (WASM) — it runs entirely in your browser, nothing is uploaded.

Recognized Functions By Category

Category	Recognized	Notes
Math & Trig	81	Local implementation
Statistical	149	Local implementation
Logical	20	Local implementation
Text	54	Local implementation
Date & Time	25	Local implementation
Lookup & Reference	39	Local implementation, including dynamic-array lookup behavior; IMAGE and RTD are unavailable service stubs
Financial	56	Includes STOCKHISTORY as an unavailable service stub
Engineering	54	Local implementation
Information	19	Includes environment-bound CELL and INFO; no unavailable service stubs in this category
Database	12	Local implementation
Web	4	ENCODEURL and FILTERXML are implemented; WEBSERVICE and PY are unavailable service stubs
Cube	7	Recognized as unavailable service stubs; live OLAP connections are outside Formulon
2024 / 2025 additions	6	Includes unavailable service stubs such as COPILOT, TRANSLATE, and DETECTLANGUAGE

Function names and localized formula text

The registry uses canonical English names. functionMetadata(name) remains the same under every profile, while localizeFunctionName(name, profileId) and localizeFormula(formula, profileId) produce the spelling a user sees in a selected Excel profile. The inverse methods return canonical names and invariant stored formula text. This separation lets an editor switch language without changing the workbook's stored formula representation. See Workbook language for the conversion boundary and Cell language switching for the interactive editor flow.

Do not pass a locale argument to functionMetadata; localization is an explicit profile-aware operation. The current profile catalog is in Locale profiles.

FILTERXML evaluates locally on Windows profiles, but returns #NAME? on mac-* profiles because Mac Excel does not provide it. WEBSERVICE is also an unknown name on Mac. A name in the catalog does not imply availability on every host.

Unavailable service stubs

These names are intentionally recognized so workbooks fail in a predictable, Excel-shaped way instead of producing #NAME? from an unknown parser path. They are outside Formulon's local calculation boundary.

Function(s)	Why it is not locally implemented	Formulon behavior
COPILOT	Requires the Microsoft 365 Copilot / LLM service	Fixed #NAME?
PY	Requires Microsoft 365's hosted Python runtime	Fixed #NAME?
IMAGE	Requires image fetching and rendering host support	Fixed #VALUE!
RTD	Requires an external Real-Time-Data provider	Fixed #N/A
STOCKHISTORY	Requires Microsoft market-data service / network I/O	Fixed #VALUE!
WEBSERVICE	Requires HTTP/network I/O	Windows: #VALUE!; Mac: #NAME?
TRANSLATE, DETECTLANGUAGE	Require cloud translation / language services	Fixed #NAME?
CUBEKPIMEMBER, CUBEMEMBER, CUBEMEMBERPROPERTY, CUBERANKEDMEMBER, CUBESET, CUBESETCOUNT, CUBEVALUE	Require a live OLAP cube connection	Fixed #N/A

Practical guidance

For an existing workbook, treat formula coverage as the first gate, not the final proof. Create a small fixture for every business-critical formula family and compare results against your target Excel profile.

Use the CLI to inspect a workbook:

formulon dump --formulas workbook.xlsx > formulas.txt

For the current oracle checks and their report commands, see Verification tracks.

Source of truth

The recognized-name list lives in tools/catalog/functions.txt. Availability annotations live in tools/catalog/function_status.tsv; omitted entries default to real local implementations. The runtime registry test verifies that recognized names resolve at runtime, while the status file prevents that recognition count from being mistaken for a local implementation count.