While Fluid Topics supports a set number of interface languages, it supports a significantly wider variety of content languages. For certain content languages, Fluid Topics supports linguistic algorithms (e.g., agglutination, stemming, etc.). The following non-exhaustive list provides details about the nature of this support.
| Language name | Language designator | Stemming dictionary | Stop words | Agglutinative support |
|---|---|---|---|---|
| Catalan, Valencian | ca | x | ||
| Czech | cs | x | x | |
| Chinese (Simplified) | zh | |||
| Chinese (Traditional) | zh | |||
| Dutch | nl | x | x | x |
| English | en | x | x | |
| Finnish | fi | x | ||
| French | fr | x | x | |
| German | de | x | x | x |
| Greek | el | |||
| Hungarian | hu | x | x | |
| Italian | it | x | x | |
| Japanese | ja | x | ||
| Korean | ko | |||
| Polish | pl | x | ||
| Portuguese | pt | x | ||
| Romanian, Moldavian, Moldovan | ro | |||
| Russian | ru | x | ||
| Spanish, Castilian | es | x | x | x |
| Swedish | sv | x | x | |
| Turkish | tr | x | x |
All language codes in Fluid Topics must include an ISO 639-1 language designator in lowercase and an officially assigned ISO 3166-1 region designator in uppercase, separated by a hyphen (e.g., en-US, fr-CA, zh-TW, etc.). ADMIN and KHUB_ADMIN users must enter the language codes when defining a content language in XML documents and in filename suffixes.