At this moment Ecwid backend is translated into these languages: 

• English (default language, enabled by default) 
• Russian 
• French 
• German 
• Italian 
• Dutch
• Hungarian 
• Norwegian 
• Spanish
• Portuguese 

These translations(except English) are still in beta, they can contain typos and errors.  So they're not enabled by default. In order to use them, you should open a special URL. Russian translation is enabled automatically based on yoru browser preferences. 

• To enable Russian specially, open this URL: my.ecwid.com/cp/CP.html?lang=ru 
• French: my.ecwid.com/cp/CP.html?lang=fr
• German: my.ecwid.com/cp/CP.html?lang=de
• Italian: my.ecwid.com/cp/CP.html?lang=it
• Dutch: my.ecwid.com/cp/CP.html?lang=nl 
• Hungarian: my.ecwid.com/cp/CP.html?lang=hu  
• Norwegian:  my.ecwid.com/cp/CP.html?lang=no 
• Spanish: my.ecwid.com/cp/CP.html?lang=es
• Portuguese: my.ecwid.com/cp/CP.html?lang=pt
• If you want to revert your backend to English, open https://my.ecwid.com/cp/CP.html?lang=en

If you find any issue with the translation, then we'd highly appreciate if you post it to our bugtracker. Thank you in advance. 

If you want to translate Ecwid backend to a new language, please translate this file: ecwid-backend-labels-7x.txt and then send the translated file to us: bizdev@ecwid.com