How to Fix ONLYOFFICE Spell Check Language Not Changing

Quick diagnosis: what is changing?

When the spell-check language in ONLYOFFICE appears to change back, first identify whether you changed the language for the whole document or only for the selected text. ONLYOFFICE exposes both controls. The document-language control applies a language to the whole document; the text-language selector applies a language to a selected passage. If only a few paragraphs need another language, select those paragraphs before changing the text language. If the setting reverts as soon as you type in ONLYOFFICE Desktop Editors, the official troubleshooting page documents that specific behavior and says an easy built-in fix is not available there yet.

This guide covers Document Editor in the browser and Desktop Editors. Names and locations can vary slightly by product, version, and integration. The steps below follow ONLYOFFICE’s current online help pages as checked October 6, 2026.

Fast checklist

1. Apply the language to the right text

Change a selected passage

1. In the document, select the word, sentence, paragraph, or other passage that needs a different spell-check language.
2. On the status bar, open the text-language selector. Choose the intended language and regional variant, such as English (United States) or English (United Kingdom).
3. Click outside the selection and inspect the status-bar language again. Type a short test sentence in the selected passage and check whether likely misspellings receive the expected red underline.

Selection matters: changing the text-language selector without selecting a passage may not change the part you meant to fix. If only some paragraphs are multilingual, set each passage deliberately. Avoid selecting the entire document unless every paragraph should use that language.

Set the language for the whole document

To apply one language across a document, click the Set Document Language control on the status bar, choose the correct language, and confirm with OK. ONLYOFFICE says this applies the selected language to the whole document and keeps it in the recently used language list. The status-bar icon may be shown as a language abbreviation, so hover over it or open the menu if you are unsure which control you have.

These instructions concern proofing language, not the interface language. Changing the menus’ display language in application settings does not by itself assign that language to document text.

2. Confirm spell checking is on

A language can be selected while spell checking is turned off, making it appear that the language selection did nothing. In Document Editor, use the spell-checking control on the status bar to turn it on. Alternatively, open File > Advanced Settings, enable Turn on spell checking, and click Apply. Misspelled words should then be marked with a red underline while you edit.

To check behavior, use a short sample with an intentionally misspelled common word in the selected language. Do not use a name, technical term, or word that may be in a custom dictionary as your only test. A missing underline can indicate that checking is disabled, that the word is accepted by the dictionary, or that the language dictionary is unavailable; it does not prove the language selector failed.

3. Stop Desktop Editors from following the keyboard language

ONLYOFFICE Desktop Editors has an application setting called Spelling language detection. With Auto, the spell-checking language is detected when you switch keyboard languages and begin typing. With Disabled, spell-check language does not depend on the keyboard language. If your language changes unexpectedly after switching input methods, open the Desktop Editors settings page, set this option to Disabled, and apply the setting. The exact settings-page layout can depend on your operating system and release.

Use Auto if you routinely type in multiple languages and want proofing to follow your keyboard input. Use Disabled if you want a stable proofing language and prefer to assign languages to document passages yourself. This setting is about keyboard-driven detection; it does not replace selecting the right document or passage language.

4. If the language resets as soon as you type

ONLYOFFICE’s Desktop Editors troubleshooting page specifically describes a default document spell-check language that switches back when the user types a character. That page says there is no easy way to change the document language for that case and that a fix was not implemented at the time of the page’s guidance; it points to a third-party workaround for setting a preferred default language. The page does not provide enough detail to recommend or validate a particular third-party workaround here.

First, update Desktop Editors to a current release and retest: the troubleshooting entry may lag behind later releases. Then test a new blank document after setting Spelling language detection to Disabled. If the language remains stable in a new file but not in one existing document, the issue may be specific to that file’s text language or formatting. Re-select the affected text and set its language. If the setting still reverts in a new file, record your Desktop Editors version, operating system, selected language, and whether keyboard input language changes at the same moment; include those details when contacting ONLYOFFICE support.

5. When a language is missing from the list

In Desktop Editors, the languages installed with the operating system appear near the top of the spell-check language list. In server deployments, the available spell-check languages depend on the dictionaries installed for that ONLYOFFICE Docs instance. A document language can exist as a selectable text property even when a proofing dictionary for that language is unavailable, so verify the language appears in the spell-checking list and actually marks test words.

For a self-hosted Docs server, ask the administrator to check the dictionaries before changing files. ONLYOFFICE’s server instructions specify that a dictionary can require matching .dic and .aff files plus a locale-named .json configuration file, a dictionary update script, service or container restart, and browser-cache clearing. Dictionary installation is an administrator task; do not upload arbitrary dictionary files into a production server. Follow the official ONLYOFFICE guide to adding custom dictionaries and verify locale and access rights with the server administrator.

Verify the fix

• Confirm whether the change is for the whole document or only selected text.
• Confirm the intended language and regional variant in the status bar.
• Check that spell checking is enabled.
• In Desktop Editors, test with keyboard-based language detection disabled if the language changes after typing.
• Use a simple test sentence with a known misspelling; check that it is underlined and that suggestions match the chosen language.
• If a required server language is absent, have the administrator verify dictionary availability instead of repeatedly changing the document setting.

ONLYOFFICE’s full Document Editor spell-checking guide explains the status-bar language controls, spell-check activation, and selected-text behavior. Desktop users can also consult the official Desktop Editors settings guide and troubleshooting page. These help pages may change as ONLYOFFICE releases updates; compare their instructions with the version installed in your environment.