The prefill key is a feature that allows you to pre-populate fields in your form so that when a user opens it, the designated field will already be filled in.
To use this key:
1. Identify the field you wish to pre-fill and copy its pre-fill key.
2. Add a "?" after your form URL and paste the key followed by an equal sign and the desired value.
For instance, your form URL would appear as follows:
https://forms.pabbly.com/form/share/41xZ-722591350?kOOrL=Pabbly
You can refer to this document: https://www.formget.com/how-to-pre-fill-form-fields/
For a detailed tutorial on using the pre-fill key, check out this video:
Pabbly Form Builder Team•Updated Aug 17, 2026•1 min read