Is LSS or QSF better for my survey?

Neither is better in general — they belong to different platforms. Use LSS if the survey will run on LimeSurvey and QSF if it will run on Qualtrics. If the questionnaire starts as a document, you can convert it to either format.

Can I convert an LSS file to a QSF file?

There is no reliable direct file-to-file converter because the formats encode platform-specific concepts. The dependable path is to convert the source questionnaire document to the target format, or rebuild via a reviewable schema.

QSF is JSON with SurveyEntry metadata and a SurveyElements array. LSS is XML that mirrors LimeSurvey database tables such as groups, questions, subquestions, and answers.

Do LSS or QSF files contain survey responses?

No. Both formats carry the survey definition only. Responses are exported separately on both platforms (for example .lsa archives in LimeSurvey or response exports in Qualtrics).

Survey format comparison

LSS vs QSF: Which Survey Format Do You Need?

LSS is the LimeSurvey survey-structure format (XML); QSF is the Qualtrics Survey Format (JSON). The right choice is decided by the platform your survey will run on — and a questionnaire document can be converted into either.

Convert to LSS Convert to QSF

Side-by-side comparison

Dimension	LimeSurvey LSS	Qualtrics QSF
Platform	LimeSurvey (open source)	Qualtrics (commercial XM platform)
Encoding	XML mirroring database tables	JSON (SurveyEntry + SurveyElements)
Core units	Groups → questions → subquestions → answers	Blocks → questions (QID) → choices/answers
Question types	Single-letter codes: L, M, T, S, F, Y, N, X…	Type + Selector pairs: MC/SAVR, TE/SL, Matrix/Likert…
Versioning	DBVersion tracks schema generation; LimeSurvey 6 uses l10ns tables	SchemaVersion 1.1.0 with generational field differences
Localization	answer_l10ns / question_l10ns tables (LimeSurvey 6)	Language payloads and translated survey copies
Response data	Not included (structure only)	Not included (structure only)
Validation	Import errors surface as database constraint failures	Field-level schema validation (e.g. ESDEF10 errors)

Choose LSS when the survey runs on LimeSurvey

LimeSurvey imports .lss files directly. A well-formed LimeSurvey 6 file stores answer text through answers plus answer_l10ns rows and stores multiple-choice options as subquestions. Older LimeSurvey installations may need a legacy variant, so check the platform version before exporting.

Because LimeSurvey is open source, LSS behavior is verifiable against the published importer code — structural mistakes such as oversized answer codes fail with database errors rather than friendly messages.

Choose QSF when the survey runs on Qualtrics

Qualtrics imports .qsf files from the Projects page or the Survey tab. Imports pass through strict field-level validation, so generated files must mirror the native export structure: complete SurveyEntry fields, unique question IDs, consistent block and flow references, and a Trash block.

Always import a generated QSF into a blank Qualtrics project first and compare the result against the source questionnaire before production use.

Converting a questionnaire into either format

If your questionnaire lives in Word, PDF, Excel, TXT, or Markdown, an AI converter can extract the questions once and export both formats. The reliable workflow is document → reviewable schema → LSS or QSF export → import into a test project → validation.

Migrating between platforms works the same way: treat the original questionnaire (not the platform file) as the source of truth, because each format encodes platform-specific logic the other cannot express.

Quick decision guide

Running on LimeSurvey? Export .lss (LimeSurvey 6 default, legacy path for older installs).

Running on Qualtrics? Export .qsf and validate in a blank project.

Undecided? Keep the questionnaire as a document — both exports stay one conversion away.

Related guides: What is an LSS file · What is a QSF file