|This page in a nutshell:
Wikidata is an international and thus multilingual project. While English is the default interface language, the project is intended to be used by, and useful for, users of every language with MediaWiki internationalization support.
Wikidata software is fully localized like all Wikimedia projects. Users can set their preferred language via the Preferences menu or the Universal Language Selector by clicking on the following icon found at the top of any page: .
Policies and guidelines should be written in English first and then translated to other languages. The English version of the policy or guideline is the authoritative version on which other language versions should be based. Translations can be made with the Translate extension. Documentation for the Translate extension is also available. You can also leave a message at Wikidata:Translators' noticeboard if you have questions or requests.
The data content of Wikidata consists of items and properties that are multilingual where necessary.
Items and properties
By default, users will view, add, and edit labels, descriptions, and aliases in their preferred language. The preferred language will also be the default language when creating new Items.
Labels, aliases, and descriptions in multiple languages can be easily added to items and properties in one of two ways:
- By using the #babel template. After setting your language skills with the #babel template (see Help:Navigating Wikidata/User Options for information on how to do this), the labels, aliases, and descriptions for your languages will now appear in the "In more languages" section of the item or property page. You can edit all or any by clicking on the  link.
- By activating the labelLister gadget in your Preferences menu (see Help:Navigating Wikidata/User Options for more information on activating gadgets). To use the labelLister gadget on an item, click on the "Label List" tab at the top right of the item page (between "Read" and "View history"). After selecting it, you will see a pop-up with a list of all labels, descriptions, and aliases available by language code. Click the  button of the pop-up to update labels, descriptions, and aliases for different languages.
For statements (including references and qualifiers), the values and properties typically do not need to be translated.
When items and properties are added to statements, they will automatically appear in the entity suggester under the appropriate translated labels for whatever language is set for the page. When adding a property or a value to a statement, you may need to enter the unique identifier (Q### or P###) of an item or property if its label has not yet been translated into the page language.
When adding Wikimedia Commons files as values, the file name will match whatever follows "File:" regardless of the language of input.
For example, for the statement
image (P18) → The_Earth_seen_from_Apollo_17.jpg The_Earth_seen_from_Apollo_17.jpg will always appear and display as the file, even when editing in French or Polish.
Sitelinks (links to Wikipedia and other Wikimedia pages) are not multilingual—they are shown and entered as on the linked site.
The gadget Main language first highlights sitelinks in the language set for the page and sorts them so they appear at the top of the list. This gadget needs to be activated in the Preferences menu. For support in additional languages, select the "Editing" tab in the Preferences menu and add "Assistant languages:" in the "Translation options" section.
- Special:MyLanguageFallbackChain displays your language fallback chain. The fallback chain refers to Wikidata's systematic way of displaying content to you when it is not available in your primary language of preference. For information on its configuration and effect see Help:Navigating Wikidata/User Options#Language fallback chain.
- Special:Search is a multilingual search engine which allows you to search for items, properties, or pages in any language.
- Item by title is for searching for items by their page titles on a Wikimedia site. It will only search for items in the selected language of the specified Wikimedia site; the title must be exactly equal to the search value entered.
- Special pages like that generate lists of items and/or properties, will show labels according to the language fallback chain, as well as identifiers (Q### for elements, P### for properties). If labels do not exist for any of the languages in your language fallback chain, only the identifier will be shown.
Items and properties without translation
As mentioned above, items and properties without labels in your preferred language will be presented using labels from other languages in your language fallback chain, or just as identifiers (Q### or P###) when no label exists in any of your languages. Please feel free to add a translation of labels (and descriptions) in such cases, but make sure the translation is correct.
Entities without label can be used as tool for finding items and properties that have no label in a given language.
For related Help pages, see:
- Help:Navigating Wikidata/User Options, which covers language settings and gadgets
For additional information and guidance, see:
- Project chat, for discussing all and any aspects of Wikidata
- Wikidata:Glossary, the glossary of terms used in this and other Help pages
- Help:FAQ, frequently asked questions asked and answered by the Wikidata community
- Help:Contents, the Help portal featuring all the documentation available for Wikidata