Form utilities
Free HTML Form Validation Checker
Paste your form HTML to check field names, required attributes, min and max ranges and whether native validation is switched off. Find gaps before visitors do.
How to use this tool
- Paste your form HTML.
- Run the check to see fields that will not submit, conflicting constraints and disabled validation.
- Apply the fixes, then mirror the same rules on your server.
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Open tool ↗Frequently asked questions
HTML form validation checker
questions.
What validation problems does it catch?
Inputs with no name that never submit, min values greater than max, required fields that are disabled, email fields without autocomplete, duplicate IDs and forms with novalidate that switch off browser checks.
Does it run my form's JavaScript?
No. The HTML is parsed in an inert template, so custom validation scripts are not executed and are not part of the check.
Is anything I enter saved or sent to Form Koi?
No. Everything you type or upload stays in this browser tab and is processed locally. Copy or download anything you want to keep before leaving the page.
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