Link Surveys
Data Prefilling in Link Surveys
Data prefilling via the URL allows you to increase conversion rate by prefilling data you already have in a different system.
Purpose
URL prefilling of data comes in handy when you:
- Have data for some of the respondents, but not all
- Have data in a different system (e.g. your database) and want to add it to the user profile in Formbricks
- Want to embed the first question in an email and increase conversion by prefilling the choice
Quick Example
Example URL
https://app.feedbackflowhq.com/s/clin3dxja02k8l80hpwmx4bjy?question_id=5
How it works
To prefill the first question of a survey, append ?question_id=answer
at the end of the survey URL. The answer has to match the expected type of the question. For example, if the first question is a rating question, the answer has to be a number. If the first question is a single select question, the answer has to be a string.
Please make sure the answer is URL encoded.
Prefill only the first question
Currently, you can only prefill the first question of a link survey.
Where do I find my question Id?
You find the questionId
in the Advanced Settings at the bottom of each question card in the Survey Editor. As you see, you can update the questionId
to any string you like. However, once you published your survey, this questionId
cannot be updated anymore:

Examples
Here are a few examples to get you started:
Rating Question
Translates to 5 stars / points / emojis
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?rating_question_id=5
NPS Question
Translates to an NPS rating of 10
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?nps_question_id=10
Single Select Question (Radio)
Chooses the option 'Very disappointed' in the single select question. The string has to be identical to the option in your question
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?single_select_question_id=Very%20disappointed
Multi Select Question (Checkbox)
Selects three options 'Sun, Palms and Beach' in the multi select question. The strings have to be identical to the options in your question
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?multi_select_question_id=Sun%2CPalms%2CBeach
Open Text Question
Adds 'I love Formbricks' as the answer to the open text question
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?openText_question_id=I%20love%20Formbricks
CTA Question
Adds 'clicked' as the answer to the CTA question. Alternatively, you can set it to 'dismissed' to skip the question.
https://app.feedbackflowhq.com/s/clin3yxja52k8l80hpwmx4bjy?cta_question_id=clicked
Validation
Make sure that the answer in the URL matches the expected type for the first question.
The URL validation works as follows:
- For Rating or NPS questions, the response is parsed as a number and verified if it's accepted by the schema.
- For CTA type questions, the valid values are "clicked" (main CTA) and "dismissed" (skip CTA).
- For Consent type questions, the valid values are "accepted" (consent given) and "dismissed" (consent not given).
- All other question types are strings.