diff --git a/src/components/ApiInfo/ApiInfo.tsx b/src/components/ApiInfo/ApiInfo.tsx
index 8b5708467d..e3df998b51 100644
--- a/src/components/ApiInfo/ApiInfo.tsx
+++ b/src/components/ApiInfo/ApiInfo.tsx
@@ -20,9 +20,16 @@ export interface ApiInfoProps {
 
 @observer
 export class ApiInfo extends React.Component<ApiInfoProps> {
+  handleDownloadClick = e => {
+    if (!e.target.href) {
+      e.target.href = this.props.store.spec.info.downloadLink;
+    }
+  };
+
   render() {
     const { store } = this.props;
     const { info, externalDocs } = store.spec;
+    const hideDownloadButton = store.options.hideDownloadButton;
 
     const downloadFilename = info.downloadFileName;
     const downloadLink = info.downloadLink;
@@ -68,10 +75,15 @@ export class ApiInfo extends React.Component<ApiInfoProps> {
           <ApiHeader>
             {info.title} <span>({info.version})</span>
           </ApiHeader>
-          {downloadLink && (
+          {!hideDownloadButton && (
             <p>
               Download OpenAPI specification:
-              <DownloadButton download={downloadFilename} target="_blank" href={downloadLink}>
+              <DownloadButton
+                download={downloadFilename}
+                target="_blank"
+                href={downloadLink || '#'}
+                onClick={this.handleDownloadClick}
+              >
                 Download
               </DownloadButton>
             </p>
diff --git a/src/services/AppStore.ts b/src/services/AppStore.ts
index 27603752d2..3ec3433f35 100644
--- a/src/services/AppStore.ts
+++ b/src/services/AppStore.ts
@@ -15,7 +15,7 @@ export interface StoreState {
     activeItemIdx: number;
   };
   spec: {
-    url: string;
+    url?: string;
     data: any;
   };
   searchIndex: any;
diff --git a/src/services/OpenAPIParser.ts b/src/services/OpenAPIParser.ts
index 84a2fc6d11..d757598201 100644
--- a/src/services/OpenAPIParser.ts
+++ b/src/services/OpenAPIParser.ts
@@ -39,7 +39,7 @@ class RefCounter {
  * Loads and keeps spec. Provides raw spec operations
  */
 export class OpenAPIParser {
-  @observable specUrl: string;
+  @observable specUrl?: string;
   @observable.ref spec: OpenAPISpec;
 
   private _refCounter: RefCounter = new RefCounter();
@@ -57,8 +57,6 @@ export class OpenAPIParser {
     const href = IS_BROWSER ? window.location.href : '';
     if (typeof specUrl === 'string') {
       this.specUrl = urlResolve(href, specUrl);
-    } else {
-      this.specUrl = href;
     }
   }
 
diff --git a/src/services/SpecStore.ts b/src/services/SpecStore.ts
index 1f9bb1d3d9..b2f210edf6 100644
--- a/src/services/SpecStore.ts
+++ b/src/services/SpecStore.ts
@@ -22,7 +22,7 @@ export class SpecStore {
 
   @computed
   get info(): ApiInfoModel {
-    return new ApiInfoModel(this.parser, this.options);
+    return new ApiInfoModel(this.parser);
   }
 
   @computed
diff --git a/src/services/models/ApiInfo.ts b/src/services/models/ApiInfo.ts
index 61ba28fec9..6e78b5e131 100644
--- a/src/services/models/ApiInfo.ts
+++ b/src/services/models/ApiInfo.ts
@@ -11,29 +11,20 @@ export class ApiInfoModel implements OpenAPIInfo {
   contact?: OpenAPIContact;
   license?: OpenAPILicense;
 
-  constructor(private parser: OpenAPIParser, private options: RedocNormalizedOptions) {
+  constructor(private parser: OpenAPIParser) {
     Object.assign(this, parser.spec.info);
   }
 
-  get downloadLink() {
-    if (this.options.hideDownloadButton) {
-      return undefined;
-    }
-
+  get downloadLink(): string | undefined {
     if (this.parser.specUrl) {
       return this.parser.specUrl;
     }
 
-    if (IS_BROWSER && window.Blob && window.URL) {
+    if (IS_BROWSER && window.Blob && window.URL && window.URL.createObjectURL) {
       const blob = new Blob([JSON.stringify(this.parser.spec, null, 2)], {
         type: 'application/json',
       });
       return window.URL.createObjectURL(blob);
-    } else if (!IS_BROWSER) {
-      return (
-        'data:application/octet-stream;base64,' +
-        new Buffer(JSON.stringify(this.parser.spec, null, 2)).toString('base64')
-      );
     }
   }
 
diff --git a/src/services/models/Operation.ts b/src/services/models/Operation.ts
index 2db8fad6db..d88059a0ca 100644
--- a/src/services/models/Operation.ts
+++ b/src/services/models/Operation.ts
@@ -11,6 +11,7 @@ import { OpenAPIExternalDocumentation, OpenAPIServer } from '../../types';
 import {
   getOperationSummary,
   getStatusCodeType,
+  IS_BROWSER,
   isAbsolutePath,
   isStatusCode,
   JsonPointer,
@@ -148,25 +149,23 @@ export class OperationModel implements IMenuItem {
   }
 }
 
-function isNumeric(n) {
-  return !isNaN(parseFloat(n)) && isFinite(n);
-}
+function normalizeServers(specUrl: string | undefined, servers: OpenAPIServer[]): OpenAPIServer[] {
+  const baseUrl = specUrl === undefined ? (IS_BROWSER ? window.location.href : '') : specUrl;
 
-function normalizeServers(specUrl: string, servers: OpenAPIServer[]): OpenAPIServer[] {
   if (servers.length === 0) {
     return [
       {
-        url: specUrl,
+        url: baseUrl,
       },
     ];
   }
 
   function normalizeUrl(url: string): string {
-    url = isAbsolutePath(url) ? url : joinPaths(specUrl, url);
+    url = isAbsolutePath(url) ? url : joinPaths(baseUrl, url);
     return stripTrailingSlash(url.startsWith('//') ? `${specProtocol}${url}` : url);
   }
 
-  const { protocol: specProtocol } = urlParse(specUrl);
+  const { protocol: specProtocol } = urlParse(baseUrl);
 
   return servers.map(server => {
     return {