> ## Documentation Index
> Fetch the complete documentation index at: https://algolia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# indexLanguages

> Languages of the indexed content, used for tokenization and normalization

export const Setting = ({type, default: defaultValue, defaultNote, scope, min, max, formerly}) => {
  const renderedDefault = defaultValue === '' ? '""' : defaultValue;
  const renderedNote = defaultNote ? `(${defaultNote})` : '';
  return <ul>
      <li><strong>Type:</strong> <code>{type}</code></li>
      <li><strong>Default:</strong> <code>{renderedDefault}</code>{renderedNote}</li>
      {min && <li><strong>Min:</strong> <code>{min}</code></li>}
      {max && <li><strong>Max:</strong> <code>{max}</code></li>}
      <li><strong>Scope:</strong> <a href="/doc/api-reference/api-parameters"><code>{scope}</code></a></li>
      {formerly && <li>
          <strong>Deprecated name:</strong> <code>{formerly}</code>
        </li>}
    </ul>;
};

<Setting type="list<enum<string>>" default="[]" scope="settings" />

The `indexLanguages` parameter specifies the languages of your indexed content.
This allows Algolia to apply language-specific processing such as tokenization,
normalization, and filtering at indexing time.

For a list of supported language ISO code, see [Supported languages](/doc/guides/managing-results/optimize-search-results/handling-natural-languages-nlp/in-depth/supported-languages).

## Usage

* Always set both `indexLanguages` and [`queryLanguages`](/doc/api-reference/api-parameters/queryLanguages) to ensure consistent processing between indexing and search.
* If `indexLanguages` isn't set:

  * Algolia uses the value of `ignorePlurals` or `removeStopWords`, if defined
  * Otherwise, it applies all supported language configurations, which may lead to unexpected results

## Example

<AccordionGroup>
  <Accordion title="Current API clients" defaultOpen="true">
    <CodeGroup>
      ```cs C# theme={"system"}
      var response = await client.SetSettingsAsync(
        "INDEX_NAME",
        new IndexSettings
        {
          IndexLanguages = new List<SupportedLanguage> { Enum.Parse<SupportedLanguage>("Ja") },
        }
      );
      ```

      ```dart Dart theme={"system"}
      final response = await client.setSettings(
        indexName: "INDEX_NAME",
        indexSettings: IndexSettings(
          indexLanguages: [
            SupportedLanguage.fromJson("ja"),
          ],
        ),
      );
      ```

      ```go Go theme={"system"}
      response, err := client.SetSettings(client.NewApiSetSettingsRequest(
        "INDEX_NAME",
        search.NewEmptyIndexSettings().SetIndexLanguages(
          []search.SupportedLanguage{search.SupportedLanguage("ja")})))
      if err != nil {
        // handle the eventual error
        panic(err)
      }
      ```

      ```java Java theme={"system"}
      UpdatedAtResponse response = client.setSettings(
        "INDEX_NAME",
        new IndexSettings().setIndexLanguages(Arrays.asList(SupportedLanguage.JA))
      );
      ```

      ```js JavaScript theme={"system"}
      const response = await client.setSettings({ indexName: 'theIndexName', indexSettings: { indexLanguages: ['ja'] } });
      ```

      ```kotlin Kotlin theme={"system"}
      var response =
        client.setSettings(
          indexName = "INDEX_NAME",
          indexSettings =
            IndexSettings(
              indexLanguages = listOf(SupportedLanguage.entries.first { it.value == "ja" })
            ),
        )
      ```

      ```php PHP theme={"system"}
      $response = $client->setSettings(
          'INDEX_NAME',
          ['indexLanguages' => [
              'ja',
          ],
          ],
      );
      ```

      ```python Python theme={"system"}
      response = client.set_settings(
          index_name="INDEX_NAME",
          index_settings={
              "indexLanguages": [
                  "ja",
              ],
          },
      )
      ```

      ```ruby Ruby theme={"system"}
      response = client.set_settings("INDEX_NAME", Algolia::Search::IndexSettings.new(index_languages: ["ja"]))
      ```

      ```scala Scala theme={"system"}
      val response = Await.result(
        client.setSettings(
          indexName = "INDEX_NAME",
          indexSettings = IndexSettings(
            indexLanguages = Some(Seq(SupportedLanguage.withName("ja")))
          )
        ),
        Duration(100, "sec")
      )
      ```

      ```swift Swift theme={"system"}
      let response = try await client.setSettings(
          indexName: "INDEX_NAME",
          indexSettings: IndexSettings(indexLanguages: [SearchSupportedLanguage.ja])
      )
      ```
    </CodeGroup>
  </Accordion>

  <Accordion title="Legacy API clients">
    <CodeGroup>
      ```cs C# theme={"system"}
      IndexSettings settings = new IndexSettings
      {
        IndexLanguages = new List { "ja" }
      };
      index.SetSettings(settings);
      ```

      ```go Go theme={"system"}
      index.SetSettings(search.Settings{
      	IndexLanguages: opt.IndexLanguages("ja"),
      })
      ```

      ```java Java theme={"system"}
      index.setSettings(new IndexSettings().setIndexLanguages(
        Arrays.asList("ja")
      ));
      ```

      ```js JavaScript theme={"system"}
      index.setSettings({ indexLanguages: ["ja"] }, (err, content) => {
        if (err) throw err;

        console.log(content);
      });
      ```

      ```kotlin Kotlin theme={"system"}
      val settings = settings {
          indexLanguages = listOf(Language.Japanese)
      }

      index.setSettings(settings)
      ```

      ```php PHP theme={"system"}
      $index->setSettings([
          'indexLanguages' => ['ja']
      ]);
      ```

      ```python Python theme={"system"}
      index.set_settings({"indexLanguages": ["ja"]})
      ```

      ```ruby Ruby theme={"system"}
      index.set_settings(
        {
          indexLanguages: ["ja"]
        }
      )
      ```

      ```scala Scala theme={"system"}
      client.execute {
        setSettings of "index_name" `with` IndexSettings(
          indexLanguages = Some(Seq("ja"))
        )
      }
      ```

      ```swift Swift theme={"system"}
      let settings = Settings()
        .set(\.indexLanguages, to: [.japanese])

      index.setSettings(settings) { result in
        if case .success(let response) = result {
          print("Response: \(response)")
        }
      }
      ```
    </CodeGroup>
  </Accordion>
</AccordionGroup>