diff --git a/README.md b/README.md
index b7a579b..96e0819 100644
--- a/README.md
+++ b/README.md
@@ -350,14 +350,15 @@ Consult the [Kroki documentation](https://kroki.io/#support) to find out which f
 
 ## Configuration
 
-| Attribute name | Description | Default value  |
-| ---- | ---- | ---- |
-| `kroki-server-url` | The URL of the Kroki server (see "Using Your Own Kroki") | `https://kroki.io`
-| `kroki-fetch-diagram` | Define if we should download (and save on the disk) the images from the Kroki server.<br/>This feature is not available when running in the browser. | `false`
-| `kroki-http-method` | Define how we should get the image from the Kroki server. Possible values:<br/><ul><li>`get`: always use GET requests</li><li>`post`: always use POST requests</li><li>`adaptive`: use a POST request if the URI length is longer than `kroki-max-uri-length` (default 4000) characters, otherwise use a GET request</li></ul> | `adaptive` |
-| `kroki-plantuml-include` | A file that will be included at the top of all PlantUML diagrams as if `!include file` was used. This can be useful when you want to define a common skin for all your diagrams. The value can be a path or a URL. |  |
-| `kroki-plantuml-include-paths` | Search path(s) that will be used to resolve `!include file` additionally to current diagram directory, similar to PlantUML property [plantuml.include.path](https://plantuml.com/de/preprocessing). Please use directory delimiter `;` (Windows) or `:` (Unix) for multiple paths, e.g.: `"c:/docu/styles;c:/docu/library"` or `"~/docu/styles:~/docu/library"` |  |
-| `kroki-max-uri-length` | Define the max URI length before using a POST request when using `adaptive` HTTP method (`kroki-http-method`) | `4000`
+| Attribute name                 | Description                                                                                                                                                                                                                                                                                                                                                     | Default value      |
+|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------|
+| `kroki-server-url`             | The URL of the Kroki server (see "Using Your Own Kroki")                                                                                                                                                                                                                                                                                                        | `https://kroki.io` |
+| `kroki-data-uri`               | Embed images as data-uri elements in HTML elements so file is completely self-contained.                                                                                                                                                                                                                                                                        | `false`            |
+| `kroki-fetch-diagram`          | Define if we should download (and save on the disk) the images from the Kroki server.<br/>This feature is not available when running in the browser.                                                                                                                                                                                                            | `false`            |
+| `kroki-http-method`            | Define how we should get the image from the Kroki server. Possible values:<br/><ul><li>`get`: always use GET requests</li><li>`post`: always use POST requests</li><li>`adaptive`: use a POST request if the URI length is longer than `kroki-max-uri-length` (default 4000) characters, otherwise use a GET request</li></ul>                                  | `adaptive`         |
+| `kroki-plantuml-include`       | A file that will be included at the top of all PlantUML diagrams as if `!include file` was used. This can be useful when you want to define a common skin for all your diagrams. The value can be a path or a URL.                                                                                                                                              |                    |
+| `kroki-plantuml-include-paths` | Search path(s) that will be used to resolve `!include file` additionally to current diagram directory, similar to PlantUML property [plantuml.include.path](https://plantuml.com/de/preprocessing). Please use directory delimiter `;` (Windows) or `:` (Unix) for multiple paths, e.g.: `"c:/docu/styles;c:/docu/library"` or `"~/docu/styles:~/docu/library"` |                    |
+| `kroki-max-uri-length`         | Define the max URI length before using a POST request when using `adaptive` HTTP method (`kroki-http-method`)                                                                                                                                                                                                                                                   | `4000`             |
 
 **❗ IMPORTANT:**
 `kroki-fetch-diagram` and `kroki-plantuml-include` are only available when safe mode is `server` or lower.
diff --git a/dist/browser/asciidoctor-kroki.js b/dist/browser/asciidoctor-kroki.js
index d312624..aab5e38 100644
--- a/dist/browser/asciidoctor-kroki.js
+++ b/dist/browser/asciidoctor-kroki.js
@@ -20057,7 +20057,7 @@ function extend() {
 },{}],70:[function(require,module,exports){
 module.exports={
   "name": "asciidoctor-kroki",
-  "version": "0.17.0",
+  "version": "0.18.1",
   "description": "Asciidoctor extension to convert diagrams to images using Kroki",
   "type": "commonjs",
   "main": "./src/asciidoctor-kroki.js",
@@ -20440,8 +20440,10 @@ const httpRequest = (XMLHttpRequest, uri, method, headers, encoding = 'utf8', bo
   try {
     const xhr = new XMLHttpRequest()
     xhr.open(method, uri, false)
-    for (const [name, value] in Object.entries(headers)) {
-      xhr.setRequestHeader(name, value)
+    if (headers) {
+      for (const [name, value] in Object.entries(headers)) {
+        xhr.setRequestHeader(name, value)
+      }
     }
     if (encoding === 'binary') {
       xhr.responseType = 'arraybuffer'
diff --git a/src/fetch.js b/src/fetch.js
index 861d7e7..84f7354 100644
--- a/src/fetch.js
+++ b/src/fetch.js
@@ -27,6 +27,7 @@ module.exports.save = function (krokiDiagram, doc, target, vfs, krokiClient) {
   const add = typeof vfs !== 'undefined' && typeof vfs.add === 'function' ? vfs.add : require('./node-fs.js').add
 
   const imagesOutputDirectory = getImagesOutputDirectory(doc)
+  const dataUri = doc.isAttribute('data-uri') || doc.isAttribute('kroki-data-uri')
   const diagramUrl = krokiDiagram.getDiagramUri(krokiClient.getServerUrl())
   const format = krokiDiagram.format
   const diagramName = `${target || 'diag'}-${rusha.createHash().update(diagramUrl).digest('hex')}.${format}`
@@ -44,7 +45,15 @@ module.exports.save = function (krokiDiagram, doc, target, vfs, krokiClient) {
     encoding = 'binary'
   }
   // file is either (already) on the file system or we should read it from Kroki
-  const contents = exists(filePath) ? read(filePath, encoding) : krokiClient.getImage(krokiDiagram, encoding)
+  let contents
+  if (exists(filePath)) {
+    contents = read(filePath, encoding)
+  } else {
+    contents = krokiClient.getImage(krokiDiagram, encoding)
+  }
+  if (dataUri) {
+    return 'data:' + mediaType + ';base64,' + Buffer.from(contents, encoding).toString('base64')
+  }
   add({
     relative: imagesOutputDirectory,
     basename: diagramName,
diff --git a/src/http/http-client.js b/src/http/http-client.js
index d7f50dd..76c71d1 100644
--- a/src/http/http-client.js
+++ b/src/http/http-client.js
@@ -4,8 +4,10 @@ const httpRequest = (XMLHttpRequest, uri, method, headers, encoding = 'utf8', bo
   try {
     const xhr = new XMLHttpRequest()
     xhr.open(method, uri, false)
-    for (const [name, value] in Object.entries(headers)) {
-      xhr.setRequestHeader(name, value)
+    if (headers) {
+      for (const [name, value] in Object.entries(headers)) {
+        xhr.setRequestHeader(name, value)
+      }
     }
     if (encoding === 'binary') {
       xhr.responseType = 'arraybuffer'
diff --git a/test/test.spec.js b/test/test.spec.js
index 72f3268..e1a78a4 100644
--- a/test/test.spec.js
+++ b/test/test.spec.js
@@ -209,6 +209,18 @@ plantuml::test/fixtures/alice.puml[png,role=sequence]
       expect(html).to.contain(`https://kroki.io/plantuml/svg/${encode(macroFile)}`)
       expect(html).to.contain('<div class="imageblock sequence kroki-format-svg kroki">')
     })
+    it('should download and embed an SVG image with kroki-fetch-diagram and kroki-data-uri', () => {
+      const registry = asciidoctor.Extensions.create()
+      asciidoctorKroki.register(registry)
+      const html = asciidoctor.convert(fs.readFileSync(fixturePath('fetch', 'doc.adoc')), {
+        attributes: {
+          'kroki-data-uri': ''
+        },
+        extension_registry: registry,
+        safe: 'unsafe'
+      })
+      expect(html).to.contain('<img src="data:image/svg+xml;base64,PD94bWwgdmVyc2l')
+    })
     it('should create diagrams in imagesdir if kroki-fetch-diagram is set', async () => {
       const registry = asciidoctor.Extensions.create()
       asciidoctorKroki.register(registry)
@@ -427,7 +439,7 @@ Bob->Alice : hello
         http.get.restore()
       }
     })
-    it('should embed an SVG image with built-in allow-uri-read and data-uri (available in Asciidoctor.js 2+)', () => {
+    it('should embed an SVG image with built-in allow-uri-read and data-uri', () => {
       const input = `
 :imagesdir: .asciidoctor/kroki
 
@@ -1276,7 +1288,7 @@ paragraph
         }
       ]
       for (const { location, pageAttr, blockAttr } of inlineOptionsFixtures) {
-        it(`should inline (via ${location}) an SVG image with built-in allow-uri-read (available in Asciidoctor.js 2+)`, () => {
+        it(`should inline (via ${location}) an SVG image with built-in allow-uri-read`, () => {
           const input = `
 :imagesdir: .asciidoctor/kroki
 ${pageAttr}
@@ -1333,7 +1345,7 @@ bytefield::test/fixtures/simple.bytefield[svg,role=bytefield${blockAttr}]
         }
       ]
       for (const { location, pageAttr, blockAttr } of interactiveOptionsFixtures) {
-        it(`should include an interactive (via ${location}) SVG image with built-in allow-uri-read and data-uri (available in Asciidoctor.js 2+)`, () => {
+        it(`should include an interactive (via ${location}) SVG image with built-in allow-uri-read and data-uri`, () => {
           const input = `
 :imagesdir: .asciidoctor/kroki
 ${pageAttr}