Prefill answers from the link
A hosted form can open with answers already filled in. Add a question key and an answer to the share link, and the visitor sees that answer selected or typed when the page loads. They can still change it before submitting.
Use it to record where people came from (a newsletter, a partner site, a campaign), or to save them typing something you already know.
Build the link
Every question has a key. Find it in the builder: select a question and look for Prefill this answer with a link, or open the Share tab and use the Prefill answers from the link card, which lists the key of every question with a Copy link button.
Add the key and the answer to the share link as a query parameter:
https://sendform.net/f/a8Kz3mXq12?f3a9c12b4=Newsletter
Combine several answers with &:
https://sendform.net/f/a8Kz3mXq12?f3a9c12b4=Ana&f7b20e1d5=Newsletter
Encode spaces and special characters as in any URL (Spring%20sale), or let your link builder do it.
How each question type is filled
| Question type | What to pass |
|---|---|
| Short answer, paragraph, email, phone, website, number, date, time | The text as is. It is cut to the question's character limit. Dates use YYYY-MM-DD, times HH:MM. |
| Dropdown, multiple choice, yes / no | The option text, matched without regard to upper or lower case. |
| Checkboxes | One or more option texts, separated by commas: ?f2d8e4a90=Figma,Notion |
| Linear scale, star rating | The number. |
| File upload | Cannot be prefilled. |
A value that does not match any option is ignored, so a typo leaves the question empty instead of breaking the form.
Good to know
- Prefilled answers go through the same checks as typed ones, and arrive in the inbox, the email notification and the webhook payload like any other answer.
- If the visitor already started this form in the same browser, their saved draft is used and the link is ignored, so nobody loses what they typed.
- Question keys stay the same when you rename a question, so links you already shared keep working. Deleting a question and adding a new one gives the new question a new key.
- Do not put private data such as passwords in a link. Links end up in browser history and server logs.