CONCAT Function in ONLYOFFICE: Combine Text, Codes and Names

=CONCAT(text1, [text2], ...)

The official reference describes up to 255 data values. That is a vendor-documented bound for these arguments, not a measured limit of every browser or desktop build. The documentation does not explicitly settle every multi-cell-array/range or long-result edge case; avoid claiming parity with Excel’s range handling without testing it.

The central rule is simple: the output is a single text result made by placing the supplied pieces side by side. There is no delimiter argument and no ignore_empty switch. To insert a dash, space, label, or punctuation mark, include it as a separate quoted value.

Create a blank test workbook in ONLYOFFICE Spreadsheet Editor. Enter the example values exactly as written; each formula can go in any otherwise unused result cell. Keep cells in column D as text before entering codes so zeros at the beginning are not stripped. Leave C3 genuinely empty (no space, no apostrophe, no formula). Avoid typing the words “blank” or “empty” into those cells.

These are artificial teaching records, not imported real customer data.

With the test data entered, place these formulas in separate blank cells:

Independent check: these expected strings were produced by ordered Python string concatenation of the fixture inputs. That proves the displayed text follows the written teaching inputs; it does not validate the ONLYOFFICE parser, cell-type coercion or version behaviour.

Human-readable labels. A lab or workshop might combine a short label with an identifier:

=CONCAT("Ticket ",D3," / ",A3)

For D3 stored as the text 0070 and A3 containing Omar, the expected result is Ticket 0070 / Omar. Do not rely on concatenation to recover leading zeroes already lost because the source cell was entered as a number. Format the code as text at data entry, or separately define an explicit numeric-to-text format after confirming that editor’s formatting behaviour.

Normalize parts before joining. If A2 came from a form and might have leading or trailing spaces, a proposed variation is:

=CONCAT(TRIM(A2)," ",B2)

The ONLYOFFICE TRIM documentation describes stripping leading/trailing spaces. With the clean sample data above, expect Nora Chen. Imported nonbreaking spaces and uncommon Unicode whitespace still require a separate check; do not assume TRIM removes every whitespace character.

Set capitalization intentionally. To uppercase the first name only:

=CONCAT(UPPER(A2),"-",B2)

The independently calculated expected result is NORA-Chen. The uppercase conversion is separately documented by ONLYOFFICE’s UPPER reference. For customer-facing names, changing case may be undesirable; inspect real names before applying this generally.

ONLYOFFICE’s CONCATENATE and TEXTJOIN entries were checked as related official resources. The names remain separate supported function entries. Migration of older formulas is optional, not a mandate to change valid workbook expressions.

All text runs together: The expression =CONCAT(A2,B2) contains no separator, so it produces NoraChen. Use =CONCAT(A2," ",B2).

The code reads 427 rather than 0427: Check whether D2 was converted to a number before CONCAT evaluated it. Text format must be applied before the value is entered or the code explicitly rebuilt with a tested formatting formula.

A formula is not recognized: Confirm the name CONCAT appears in the target installation’s formula wizard and that the file is opened with the Spreadsheet Editor. The current documentation does not prove availability in every old installation. Distinguish an unsupported name from incorrectly typed quotation marks and separators.

A source cell already contains an error: Test with the smallest input first. An input error and a formula syntax failure are different causes. The vendor’s short CONCAT reference does not specify all error-propagation rules; this guide does not invent an observed error code.

Empty and formula-empty cells: A genuinely empty cell is not identical to ="", whitespace text, or a 0. The treatment of each case in an arbitrary concatenation/range must be checked natively before building validation rules. If you need empty-value control, start with TEXTJOIN’s documented ignore_empty parameter.

Very long output or array references: Microsoft’s Excel CONCAT article documents range behaviour and an Excel output-length error. That is Excel evidence, not proof of an identical ONLYOFFICE length limit, array order, or error string. Keep imported-workbook tests separate from the straightforward scalar cases here.

• ONLYOFFICE: the current help documents CONCAT(text1, [text2], ...), up to 255 values, without a built-in delimiter. Minimum supported version and Desktop/web parity: not confirmed.
• Microsoft Excel: Microsoft’s CONCAT documentation shows scalar and range inputs, including full-column and rectangular range cases, plus Excel-specific limits. No such advanced ONLYOFFICE range assertions are made here.
• Google Sheets: Google’s CONCAT reference uses exactly two arguments (value1, value2). A multi-argument formula like the five-piece example above therefore requires rewriting for Sheets, perhaps with CONCATENATE or TEXTJOIN.

The formulas use English function names, double-quoted text and commas between arguments, matching the current English ONLYOFFICE function-entry instructions. The Advanced Settings guide documents adjustable formula language and regional settings; do not assume your editor uses the same formula spelling, argument separator or number presentation. If commas are rejected in your locale, inspect the editor’s function wizard/tooltip rather than replacing characters blindly. These particular outputs contain literal text, so their punctuation is intentional data rather than locale number formatting.

The accessible official function help is unversioned. Inclusion in today’s documentation does not establish the minimum supported Desktop Editors release, server-side Docs release, connector build, or universal parity. ONLYOFFICE announced Docs 10.0 on October 10, 2026, but no native Docs 10.0 or Desktop execution has been performed for this guide. Record the actual installed version when reproducing the tests.

Will CONCAT insert a comma automatically? No. Use =CONCAT(B2,", ",A2) or consider TEXTJOIN when a constant separator belongs between many inputs.

Does CONCAT protect a text identifier’s leading zeroes? It can concatenate text that already contains zeroes, but cannot safely reconstruct zeroes after numeric conversion.

Can I paste an Excel CONCAT range formula unchanged? Some formulas may transfer; verify range handling in the target ONLYOFFICE version. The vendor help used for this article is not a native range-behaviour test.

• ONLYOFFICE CONCAT: syntax and maximum values — accessed 2026-10-13; vendor unversioned English help.
• ONLYOFFICE CONCATENATE: predecessor name — accessed 2026-10-13.
• ONLYOFFICE TEXTJOIN: delimiter and empties — accessed 2026-10-13.
• ONLYOFFICE function wizard and comma examples — accessed 2026-10-13.
• ONLYOFFICE regional and formula language settings — accessed 2026-10-13.
• Microsoft Excel CONCAT and Google Sheets CONCAT — accessed 2026-10-13; only for explicitly labelled cross-application differences.

Verification limitations: Scalar examples were independently calculated. Native Desktop/web execution, range handling, empty/error input behavior, localization and historical release support remain untested.