# Logon Language abap2UI5 picks the user's logon language automatically from the SAP session — every text element, every OData/CDS label, every message class is returned in that language. For most applications no extra configuration is required. ## Override the Backend Language To force a specific SAP logon language at startup, append the `sap-language` URL parameter: ``` …/z2ui5/sample?sap-language=EN …/z2ui5/sample?sap-language=DE ``` The value is a two-character ISO 639-1 language code, e.g. `EN`, `DE`, `FR`, `JA` (SAP's internal one-character language keys also work). The server sets the user's session language for this request, so backend reads, OData calls and translated texts all use that locale. ## Override the UI5 Frontend Locale The UI5 framework keeps a *separate* locale for date and number formatting, control labels ("Search", "Cancel", …) and the calendar week. By default UI5 derives it from the browser. You can pin it with the URL parameter `sap-ui-language`: ``` …/z2ui5/sample?sap-ui-language=de ``` Most apps don't need this — the browser locale and the SAP logon language agree in practice. Set it explicitly when you need full control, e.g. in test environments. ## Forcing the Frontend Locale at Startup You can also pin the UI5 locale via the bootstrap, instead of relying on a URL parameter: ```abap METHOD z2ui5_if_ui5_exit~set_config_http_get. cs_config-t_add_config = VALUE #( ( n = `data-sap-ui-language` v = `en` ) ). ENDMETHOD. ``` See [Bootstrap Attributes](/configuration/setup/bootstrap_attributes) for more on this mechanism. ## See Also - [SAP URL parameter reference](https://help.sap.com/doc/saphelp_nw75/7.5.5/en-US/8b/46468c433b40c3b87b2e07f34dea1b/content.htm?no_cache=true) — full list of supported parameters. - Official UI5 documentation on [language and locale](https://sapui5.hana.ondemand.com/#/topic/91f21f176f4d1014b6dd926db0e91070).