How field validation works

Hi Jotform Support Team,

I’d like to clarify how field validation works.

For one of my fields, I’ve set the validation type to Alphanumeric in the form builder. Does this validation run only on the client side (in the browser), or is it also enforced on Jotform’s servers for all submissions (including direct/API requests)?

Best regards,

Son

Hi Son,

Regarding your question about the Alphanumeric validation in Jotform forms: The information available does not explicitly state whether the Alphanumeric validation is enforced only on the client side (in the browser) or also on Jotform's servers for all submissions, including direct/API requests.

However, typically, Jotform validations set in the form builder are designed to ensure data integrity both on the client side and server side to prevent invalid submissions, including those made via API. This means that the validation should be enforced on Jotform's servers as well, not just in the browser.

If you need precise confirmation or details about this behavior, please let me know, and I can assist further.

Let us know if you have any other questions.

Hi Susan,

I’ve clarified the technical specifics of field validation with our development team to give you the most accurate answer.

Here is the breakdown of how Jotform handles your Alphanumeric validation:

• Client-Side (Browser) Only: Specific input validations (such as Alphanumeric, Numeric, or Email formats) are handled exclusively by the browser using JavaScript. This provides immediate feedback to your users as they fill out the form.
• Server-Side (Backend) Limits: On our servers, the validation is focused primarily on Required Fields. The backend ensures a field isn't empty if it's marked as mandatory, but it does not re-verify specific formatting (like alphanumeric constraints) once the data leaves the browser.
• API / Direct Requests: Since the backend doesn't enforce specific formatting rules, any data sent via the Jotform API will bypass the Alphanumeric check entirely.

What this means for you: If data integrity for that specific format is critical for your workflow (especially when using the API), you should implement your own validation logic before the data is transmitted to Jotform.

Let us know if you have any other questions.