The LSS file is LimeSurvey's native survey structure format. If you work with LimeSurvey, you will use LSS files for backups, migrations, environment transfers, and platform conversions. This guide covers everything: what an LSS file contains, how to export and import one, how to convert it to Qualtrics or other platforms, and how it compares to the QSF format used by Qualtrics.
What Is an LSS File?
An LSS file (LimeSurvey Structure file) is an XML-based export format that captures the complete structure of a LimeSurvey survey. It stores every question, group, answer option, relevance condition, and survey setting in a single portable file. Export a survey as LSS, move the file to another LimeSurvey instance, and import it to recreate the survey exactly.
What LSS contains : and what it does not
Contains: Question groups, questions, subquestions, answer options, display logic (relevance equations), survey settings, language configuration, quotas.
Does not contain: Response data, participant lists, collected answers, tokens, or any data submitted by respondents.
What Is Inside an LSS File
LSS files are valid XML. Open one in any text editor and you will see a structured document with these key elements:
| XML Element | What It Stores | Example Content |
|---|---|---|
<surveys> | Survey-level settings | Title, language, format, navigation type |
<groups> | Question groups | Group name, description, display order |
<questions> | Individual questions | Type code, title, text, mandatory flag |
<subquestions> | Matrix rows and sub-items | Row labels for matrix and ranking questions |
<answers> | Answer options | Answer code, text, sort order |
<conditions> | Branching logic | Display conditions between questions |
<defaultvalues> | Pre-filled answers | Default response values |
<quotas> | Quota settings | Quota limits per answer option |
LimeSurvey Question Type Codes in LSS
Every question in an LSS file has a type code. These are the most common ones you will encounter:
| Type Code | Question Type | Qualtrics Equivalent |
|---|---|---|
L | Single choice (radio) | MC:SingleAnswer |
M | Multiple choice (checkbox) | MC:MultipleAnswer |
S | Short free text | TE:SingleLine |
T | Long free text | TE:Essay |
F | Array (5-point Likert) | Matrix |
B | Array (10-point scale) | Matrix |
! | Dropdown list | MC:SingleAnswer (dropdown) |
X | Text display (descriptive) | DB (Descriptive Block) |
R | Ranking | RankOrder |
N | Numerical input | TE:SingleLine (validated) |
How to Export an LSS File from LimeSurvey
- 1Open your surveyLog in to LimeSurvey and open the survey you want to export from the Surveys list.
- 2Go to Survey > ExportIn the top navigation, click Survey, then Export.
- 3Select Export survey structure (.lss)Choose Export survey structure (.lss). LimeSurvey generates and downloads the .lss file immediately.
How to Import an LSS File into LimeSurvey
- 1Go to Create Survey > ImportIn LimeSurvey, go to the Surveys list. Click Create a new survey and select the Import tab.
- 2Upload the LSS fileClick Choose file, select your .lss file, and click Import survey.
- 3Review in the survey editorLimeSurvey rebuilds the survey from the LSS file. Review all question groups, logic, and settings before activating the survey.
LSS vs QSF: Key Differences
| Feature | LSS (.lss) | QSF (.qsf) |
|---|---|---|
| Platform | LimeSurvey | Qualtrics |
| File format | XML | JSON |
| Contains response data | No | No |
| Contains logic/conditions | Yes (relevance equations) | Yes (display logic) |
| Directly interchangeable | No : requires conversion | No : requires conversion |
| Open with | LimeSurvey, any XML editor | Qualtrics, any JSON editor |
| Convert to other platforms | Via Pirai AI (coming soon) | Via Pirai AI (live now) |
How to Convert an LSS File to Another Platform
The most common conversion need is LSS to Qualtrics QSF : moving a LimeSurvey survey into Qualtrics when an institution switches platforms. The second most common is LSS to other survey platforms for multi-platform research.
| Migration | Output Format | Guide |
|---|---|---|
| LimeSurvey to Qualtrics | .qsf | Migration guide |
| LimeSurvey to REDCap | .csv Data Dictionary | Import guide |
| LimeSurvey to SurveyMonkey | .txt Paste Your Content | Import guide |
| LimeSurvey to Google Forms | .txt Apps Script | Import guide |
| LimeSurvey to Microsoft Forms | .docx Quick Import | Import guide |
LSS direct upload coming soon to Pirai AI. Currently, export your LimeSurvey survey as LSS, then use the LSS file as input. When direct LSS upload launches, conversion to all 20+ platforms will be available in one step from the LSS file. Sign up at platform.piraiai.com to be notified.
Migrate your LimeSurvey surveys to Qualtrics, REDCap, or 20+ other platforms.
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Related Resources
For a shorter overview, see What Is an LSS File?. For the QSF equivalent, see What Is a QSF File? Complete Guide. For migrating from LimeSurvey to Qualtrics, see How to Migrate from LimeSurvey to Qualtrics. For the full migration reference, see the Survey Platform Migration Guide.