LSS File Extension Guide
The .lss file extension identifies a LimeSurvey survey structure file. It is an XML-based format for moving, checking, and recreating survey questionnaires in LimeSurvey.
What the LSS extension means
Files ending in .lss are LimeSurvey structure files. They describe the questionnaire design so LimeSurvey can import groups, questions, subquestions, answer options, settings, and logic.
The extension is commonly used for survey backup, migration between LimeSurvey instances, and generated survey drafts created from source documents.
LSS files are XML-based
An LSS file can be opened as text because it stores XML. Inside, you may see survey settings, language data, question groups, question records, answer records, relevance equations, and other LimeSurvey fields.
Open, check, or convert an LSS file
If you already have an LSS file, inspect it before import to check question order, answer codes, groups, and logic. If your survey starts in Word, DOCX, PDF, or TXT, convert it to LSS first and then inspect the generated structure.
This keeps the LimeSurvey import file separate from the review step, which is especially important for matrix questions, branching, and multilingual surveys.
LSS extension facts
Extension: .lss
Platform: LimeSurvey
Structure: XML survey definition
Use case: import, export, migration, review, and conversion.