diff --git a/.changeset/string-inputs-update.md b/.changeset/string-inputs-update.md
new file mode 100644
index 000000000..01fe64157
--- /dev/null
+++ b/.changeset/string-inputs-update.md
@@ -0,0 +1,5 @@
+---
+'@workflowbuilder/sdk': patch
+---
+
+Empty strings are marked as invalid for required string inputs. The TextArea is highlighted.
diff --git a/packages/sdk/src/features/json-form/controls/text-area-control/text-area-control.tsx b/packages/sdk/src/features/json-form/controls/text-area-control/text-area-control.tsx
index 3af41883f..7d6d7f316 100644
--- a/packages/sdk/src/features/json-form/controls/text-area-control/text-area-control.tsx
+++ b/packages/sdk/src/features/json-form/controls/text-area-control/text-area-control.tsx
@@ -6,7 +6,7 @@ import { createControlRenderer } from '../../utils/rendering';
 import { ControlWrapper } from '../control-wrapper';
 
 function TextAreaControl(props: TextAreaControlProps) {
-  const { data, handleChange, path, enabled, uischema } = props;
+  const { data, handleChange, path, enabled, uischema, errors } = props;
   const { placeholder, minRows, maxRows, disabled } = uischema;
   const isDisabled = !enabled || disabled === true;
 
@@ -35,6 +35,7 @@ function TextAreaControl(props: TextAreaControlProps) {
         onChange={onChange}
         onBlur={onBlur}
         size="medium"
+        error={errors.length > 0}
       />
     </ControlWrapper>
   );
diff --git a/packages/sdk/src/features/json-form/controls/text-control/text-control.tsx b/packages/sdk/src/features/json-form/controls/text-control/text-control.tsx
index 15fe5a00f..f78c0dc4d 100644
--- a/packages/sdk/src/features/json-form/controls/text-control/text-control.tsx
+++ b/packages/sdk/src/features/json-form/controls/text-control/text-control.tsx
@@ -32,10 +32,7 @@ function TextControl(props: TextControlProps) {
   function onBlur() {
     const trimmed = inputValue.trim();
 
-    if (trimmed === '') {
-      // eslint-disable-next-line unicorn/no-useless-undefined
-      handleChange(path, undefined);
-    } else if (isNumberInput) {
+    if (isNumberInput) {
       const number_ = Number(trimmed);
       handleChange(path, Number.isNaN(number_) ? undefined : number_);
     } else {
diff --git a/packages/sdk/src/utils/validation/workflow-builder-validator.ts b/packages/sdk/src/utils/validation/workflow-builder-validator.ts
index a6e4c645f..af0742c93 100644
--- a/packages/sdk/src/utils/validation/workflow-builder-validator.ts
+++ b/packages/sdk/src/utils/validation/workflow-builder-validator.ts
@@ -91,7 +91,11 @@ function createValidateFunction(schema: object): ValidateFunction {
   const validator = new Validator(schema as Schema, '7', false);
 
   const validateFn = (data: unknown): boolean => {
-    const result = validator.validate(data);
+    // Default schema accepts '' string as valid for required this, clears those values and prompts required.
+    const formattedData = Object.fromEntries(
+      Object.entries(data || {}).filter(([, value]) => !(typeof value === 'string' && value.trim() === '')),
+    );
+    const result = validator.validate(formattedData);
     validateFn.errors = result.valid ? null : mapOutputToErrorObjects(result.errors);
     return result.valid;
   };