diff --git a/packages/@sanity/form-builder/src/inputs/NumberInput.js b/packages/@sanity/form-builder/src/inputs/NumberInput.js
index 1686a059474..4842c00aded 100644
--- a/packages/@sanity/form-builder/src/inputs/NumberInput.js
+++ b/packages/@sanity/form-builder/src/inputs/NumberInput.js
@@ -2,6 +2,7 @@
 import React from 'react'
 import TextInput from 'part:@sanity/components/textinputs/default'
 import FormField from 'part:@sanity/components/formfields/default'
+import {getValidationRule} from '../utils/getValidationRule'
 import PatchEvent, {set, unset} from '../PatchEvent'
 import type {Type, Marker} from '../typedefs'
 
@@ -39,18 +40,8 @@ export default class NumberInput extends React.Component<Props> {
     const errors = validation.filter(marker => marker.level === 'error')
 
     // Show numpad on mobile if only positive numbers is preferred
-    let onlyPositiveNumber = false
-    if (type && type.validation && type.validation.length) {
-      type.validation.forEach(rule => {
-        if (rule._rules && rule._rules.length) {
-          rule._rules.forEach(_r => {
-            if (_r.flag === 'min' && _r.constraint >= 0) {
-              onlyPositiveNumber = true
-            }
-          })
-        }
-      })
-    }
+    const minRule = getValidationRule(type, 'min')
+    const onlyPositiveNumber = minRule && minRule.constraint >= 0
 
     return (
       <FormField markers={markers} level={level} label={type.title} description={type.description}>
@@ -63,7 +54,7 @@ export default class NumberInput extends React.Component<Props> {
           onChange={this.handleChange}
           onFocus={onFocus}
           ref={this.setInput}
-          pattern={onlyPositiveNumber ? '[\d]*' : undefined}
+          pattern={onlyPositiveNumber ? '[d]*' : undefined}
         />
       </FormField>
     )
diff --git a/packages/@sanity/form-builder/src/inputs/UrlInput.js b/packages/@sanity/form-builder/src/inputs/UrlInput.js
index 21406801c7b..be00bbd560f 100644
--- a/packages/@sanity/form-builder/src/inputs/UrlInput.js
+++ b/packages/@sanity/form-builder/src/inputs/UrlInput.js
@@ -1,7 +1,9 @@
 //@flow
 import React from 'react'
+import {get} from 'lodash'
 import TextInput from 'part:@sanity/components/textinputs/default'
 import FormField from 'part:@sanity/components/formfields/default'
+import {getValidationRule} from '../utils/getValidationRule'
 import PatchEvent, {set, unset} from '../PatchEvent'
 import type {Type, Marker} from '../typedefs'
 
@@ -38,11 +40,15 @@ export default class UrlInput extends React.Component<Props> {
     const validation = markers.filter(marker => marker.type === 'validation')
     const errors = validation.filter(marker => marker.level === 'error')
 
+    // Use text input for relative URIs
+    const uriRule = getValidationRule(type, 'uri')
+    const inputType = uriRule && get(uriRule, 'constraint.options.allowRelative') ? 'text' : 'url'
+
     return (
       <FormField markers={markers} level={level} label={type.title} description={type.description}>
         <TextInput
           customValidity={errors && errors.length > 0 ? errors[0].item.message : ''}
-          type="url"
+          type={inputType}
           value={value}
           readOnly={readOnly}
           placeholder={type.placeholder}
diff --git a/packages/@sanity/form-builder/src/utils/getValidationRule.js b/packages/@sanity/form-builder/src/utils/getValidationRule.js
new file mode 100644
index 00000000000..251316609a4
--- /dev/null
+++ b/packages/@sanity/form-builder/src/utils/getValidationRule.js
@@ -0,0 +1,23 @@
+import type {Type} from '../typedefs'
+
+export function getValidationRule(type: Type, ruleName: string) {
+  if (!type || !type.validation || !type.validation.length) {
+    return null
+  }
+
+  for (let i = 0; i < type.validation.length; i++) {
+    const validation = type.validation[i]
+    if (!validation || !validation._rules) {
+      continue
+    }
+
+    for (let r = 0; r < validation._rules.length; r++) {
+      const rule = validation._rules[r]
+      if (rule.flag === ruleName) {
+        return rule
+      }
+    }
+  }
+
+  return null
+}
diff --git a/packages/test-studio/schemas/validation.js b/packages/test-studio/schemas/validation.js
index 56ec18cafce..7dc5283de39 100644
--- a/packages/test-studio/schemas/validation.js
+++ b/packages/test-studio/schemas/validation.js
@@ -52,6 +52,13 @@ export default {
       description: 'URL that only allows mailto: and tel: schemes',
       validation: Rule => Rule.uri({scheme: ['mailto', 'tel']})
     },
+    {
+      name: 'relativeUrl',
+      type: 'url',
+      title: 'Relative URL',
+      description: 'URL that allows relative URLs',
+      validation: Rule => Rule.uri({allowRelative: true})
+    },
     {
       name: 'date',
       type: 'datetime',
@@ -89,6 +96,12 @@ export default {
       description: 'Only positive numbers larger than lowest temperature',
       validation: Rule => Rule.positive().min(Rule.valueOfField('lowestTemperature'))
     },
+    {
+      name: 'onlyPositive',
+      type: 'number',
+      title: 'Only positive',
+      validation: Rule => Rule.positive()
+    },
     {
       name: 'someInteger',
       type: 'number',