diff --git a/gh-badges/README.md b/gh-badges/README.md
index 048b6e5c2531b..3cbb77362fc53 100644
--- a/gh-badges/README.md
+++ b/gh-badges/README.md
@@ -21,7 +21,7 @@ badge build passed :green .png > mybadge.png
 ### As a library
 
 ```js
-const { BadgeFactory } = require('gh-badges')
+const { BadgeFactory, ValidationError } = require('gh-badges')
 
 const bf = new BadgeFactory()
 
@@ -31,7 +31,8 @@ const format = {
   template: 'flat',
 }
 
-const svg = bf.create(format)
+bf.create(format) //<svg...
+bf.create({}) // ValidationError: Field `text` is required
 ```
 
 ### Node version support
diff --git a/gh-badges/lib/index.js b/gh-badges/lib/index.js
index 2ec589d6fde17..6880460162774 100644
--- a/gh-badges/lib/index.js
+++ b/gh-badges/lib/index.js
@@ -5,6 +5,8 @@
 
 const makeBadge = require('./make-badge')
 
+class ValidationError extends Error {}
+
 /**
  * BadgeFactory
  */
@@ -17,6 +19,56 @@ class BadgeFactory {
     }
   }
 
+  _validate(format) {
+    if (!('text' in format)) {
+      throw new ValidationError('Field `text` is required')
+    }
+
+    if (
+      !Array.isArray(format.text) ||
+      format.text.length !== 2 ||
+      typeof format.text[0] !== 'string' ||
+      typeof format.text[1] !== 'string'
+    ) {
+      throw new ValidationError('Field `text` must be an array of 2 strings')
+    }
+
+    const stringFields = [
+      'labelColor',
+      'color',
+      'colorA',
+      'colorscheme',
+      'colorB',
+    ]
+    stringFields.forEach(function(field) {
+      if (field in format && typeof format[field] !== 'string') {
+        throw new ValidationError(`Field \`${field}\` must be of type string`)
+      }
+    })
+
+    const formatValues = ['svg', 'json']
+    if ('format' in format && !formatValues.includes(format.format)) {
+      throw new ValidationError(
+        `Field \`format\` must be one of (${formatValues.toString()})`
+      )
+    }
+
+    const templateValues = [
+      'plastic',
+      'flat',
+      'flat-square',
+      'for-the-badge',
+      'popout',
+      'popout-square',
+      'social',
+    ]
+    if ('template' in format && !templateValues.includes(format.template)) {
+      throw new ValidationError(
+        `Field \`template\` must be one of (${templateValues.toString()})`
+      )
+    }
+  }
+
   /**
    * Create a badge
    *
@@ -34,6 +86,7 @@ class BadgeFactory {
    * @see https://github.com/badges/shields/tree/master/gh-badges/README.md
    */
   create(format) {
+    this._validate(format)
     return makeBadge(format)
   }
 }
diff --git a/gh-badges/lib/index.spec.js b/gh-badges/lib/index.spec.js
index 68a6e7d3b17ae..1573e938f7423 100644
--- a/gh-badges/lib/index.spec.js
+++ b/gh-badges/lib/index.spec.js
@@ -2,12 +2,17 @@
 
 const { expect } = require('chai')
 const isSvg = require('is-svg')
-const { BadgeFactory } = require('.')
+const { BadgeFactory, ValidationError } = require('.')
 
 const bf = new BadgeFactory()
 
 describe('BadgeFactory class', function() {
   it('should produce badge with valid input', function() {
+    expect(
+      bf.create({
+        text: ['build', 'passed'],
+      })
+    ).to.satisfy(isSvg)
     expect(
       bf.create({
         text: ['build', 'passed'],
@@ -16,5 +21,37 @@ describe('BadgeFactory class', function() {
         template: 'flat',
       })
     ).to.satisfy(isSvg)
+    expect(
+      bf.create({
+        text: ['build', 'passed'],
+        foo: 'bar', // extra key
+      })
+    ).to.satisfy(isSvg)
+  })
+
+  it('should throw a ValidationError with invalid inputs', function() {
+    expect(() => bf.create({})).to.throw(
+      ValidationError,
+      'Field `text` is required'
+    )
+    expect(() => bf.create({ text: ['build'] })).to.throw(
+      ValidationError,
+      'Field `text` must be an array of 2 strings'
+    )
+    expect(() =>
+      bf.create({ text: ['build', 'passed', 'something else'] })
+    ).to.throw(ValidationError, 'Field `text` must be an array of 2 strings')
+    expect(() =>
+      bf.create({ text: ['build', 'passed'], labelColor: 7 })
+    ).to.throw(ValidationError, 'Field `labelColor` must be of type string')
+    expect(() =>
+      bf.create({ text: ['build', 'passed'], format: 'png' })
+    ).to.throw(ValidationError, 'Field `format` must be one of (svg,json)')
+    expect(() =>
+      bf.create({ text: ['build', 'passed'], template: 'something else' })
+    ).to.throw(
+      ValidationError,
+      'Field `template` must be one of (plastic,flat,flat-square,for-the-badge,popout,popout-square,social)'
+    )
   })
 })