diff --git a/oauth-1.0a.d.ts b/oauth-1.0a.d.ts
index f40cb3d..4a04d5d 100644
--- a/oauth-1.0a.d.ts
+++ b/oauth-1.0a.d.ts
@@ -17,6 +17,16 @@ declare class OAuth {
   signature_metho: string;
   version: string;
 
+  static urlPattern: RegExp;
+
+  /**
+   * Parse an URL into its various component.
+   *
+   * Does no normalisation but throw if it encounters non-ascii char or if the
+   * URL does represent a http(s) request.
+   */
+  static parseUrl(url: string): OAuth.URL;
+
   constructor(opts?: OAuth.Options);
 
   /**
@@ -189,4 +199,17 @@ declare namespace OAuth {
     secret: string;
   }
 
+  /**
+   * URL components
+   */
+  export interface URL {
+    auth: string;
+    hash: string;
+    hostname: string;
+    pathname: string;
+    port: string;
+    protocol: 'http' | 'https';
+    search: string;
+  }
+
 }
diff --git a/oauth-1.0a.js b/oauth-1.0a.js
index 5c15dd4..8e89a87 100644
--- a/oauth-1.0a.js
+++ b/oauth-1.0a.js
@@ -48,6 +48,37 @@ function OAuth(opts) {
     this.body_hash_function = opts.body_hash_function || this.hash_function;
 }
 
+// Static methods and properties.
+Object.defineProperties(OAuth, {
+
+    // cache the url regexp.
+    urlPattern: {
+        value: /^(https?):\/\/([^:]+:[^@]+@)?([^:/?#]+)(\:\d+)?(\/[^?#]*)?(\?[^#]*)?(#.*)?$/
+    },
+
+    // Parse url into components.
+    parseUrl: {
+        value: function(url) {
+            var match = OAuth.urlPattern.exec(url);
+            var components;
+
+            if (match == null || match.len < 8) {
+                throw new Error('Invalid URL: "' + url + '".');
+            }
+
+            return {
+                protocol: match[1],
+                auth: match[2] || '',
+                hostname: match[3],
+                port: match[4] || '',
+                pathname: match[5] || '',
+                search: match[6] || '',
+                hash: match[7] || ''
+            };
+        }
+    }
+});
+
 /**
  * OAuth request authorize
  * @param  {Object} request data
@@ -194,7 +225,18 @@ OAuth.prototype.getSigningKey = function(token_secret) {
  * @return {String}
  */
 OAuth.prototype.getBaseUrl = function(url) {
-    return url.split('?')[0];
+    var parsed = OAuth.parseUrl(url);
+    var port = parsed.port;
+    var protocol = parsed.protocol.toLowerCase();
+
+    if (
+        (port === ':80' && protocol === 'http') ||
+        (port === ':443' && protocol === 'https')
+    ) {
+        parsed.port = '';
+    }
+
+    return parsed.protocol + '://' + parsed.auth + parsed.hostname + parsed.port + parsed.pathname;
 };
 
 /**
diff --git a/test/getBaseUrl.js b/test/getBaseUrl.js
new file mode 100644
index 0000000..3ff9fa8
--- /dev/null
+++ b/test/getBaseUrl.js
@@ -0,0 +1,29 @@
+var expect = require('chai').expect;
+var OAuth = require('../oauth-1.0a');
+
+describe('#getBaseUrl', function() {
+	var oauth = new OAuth({consumer: {}});
+
+	beforeEach(function () {
+		oauth = new OAuth({consumer: {}});
+  });
+
+  it('should return base url', function () {
+    expect(oauth.getBaseUrl('http://example.com/path/')).to.equal('http://example.com/path/');
+    expect(oauth.getBaseUrl('http://example.com/path/?foo=bar')).to.equal('http://example.com/path/');
+  });
+
+  it('should exclude default port number', function () {
+    expect(oauth.getBaseUrl('http://example.com/')).to.equal('http://example.com/');
+    expect(oauth.getBaseUrl('http://example.com:80/')).to.equal('http://example.com/');
+    expect(oauth.getBaseUrl('https://example.com/')).to.equal('https://example.com/');
+    expect(oauth.getBaseUrl('https://example.com:443/')).to.equal('https://example.com/');
+  });
+
+  it('should include non-default port number', function () {
+    expect(oauth.getBaseUrl('http://example.com:8080/')).to.equal('http://example.com:8080/');
+    expect(oauth.getBaseUrl('http://example.com:443/')).to.equal('http://example.com:443/');
+    expect(oauth.getBaseUrl('https://example.com:8080/')).to.equal('https://example.com:8080/');
+    expect(oauth.getBaseUrl('https://example.com:80/')).to.equal('https://example.com:80/');
+  });
+});
diff --git a/test/parseUrl.js b/test/parseUrl.js
new file mode 100644
index 0000000..afe89fb
--- /dev/null
+++ b/test/parseUrl.js
@@ -0,0 +1,46 @@
+var expect = require('chai').expect;
+var OAuth = require('../oauth-1.0a');
+
+describe('OAuth.parseUrl', function() {
+
+  it('should parse protocol', function () {
+    expect(OAuth.parseUrl('http://example.com/').protocol).to.equal('http');
+    expect(OAuth.parseUrl('https://example.com/').protocol).to.equal('https');
+  });
+
+  it('should parse auth component', function () {
+    expect(OAuth.parseUrl('http://example.com/').auth).to.equal('');
+    expect(OAuth.parseUrl('http://foo:bar@example.com/').auth).to.equal('foo:bar@');
+  });
+
+  it('should parse hostname component', function () {
+    expect(OAuth.parseUrl('http://example.com/').hostname).to.equal('example.com');
+    expect(OAuth.parseUrl('http://example.com:8080/').hostname).to.equal('example.com');
+    expect(OAuth.parseUrl('http://foo:bar@example.com/').hostname).to.equal('example.com');
+  });
+
+  it('should parse port component', function () {
+    expect(OAuth.parseUrl('http://example.com/').port).to.equal('');
+    expect(OAuth.parseUrl('http://example.com:80/').port).to.equal(':80');
+    expect(OAuth.parseUrl('http://foo:bar@example.com:80/').port).to.equal(':80');
+  });
+
+  it('should parse pathname component', function () {
+    expect(OAuth.parseUrl('http://example.com').pathname).to.equal('');
+    expect(OAuth.parseUrl('http://example.com/').pathname).to.equal('/');
+    expect(OAuth.parseUrl('http://example.com/foo/bar').pathname).to.equal('/foo/bar');
+  });
+
+  it('should parse search component', function () {
+    expect(OAuth.parseUrl('http://example.com').search).to.equal('');
+    expect(OAuth.parseUrl('http://example.com/?foo').search).to.equal('?foo');
+    expect(OAuth.parseUrl('http://example.com/?foo#bar').search).to.equal('?foo');
+    expect(OAuth.parseUrl('http://example.com/?foo?bar').search).to.equal('?foo?bar');
+  });
+
+  it('should parse hash component', function () {
+    expect(OAuth.parseUrl('http://example.com').hash).to.equal('');
+    expect(OAuth.parseUrl('http://example.com/?foo').hash).to.equal('');
+    expect(OAuth.parseUrl('http://example.com/?foo#bar').hash).to.equal('#bar');
+  });
+});
diff --git a/test/services/twitter.js b/test/services/twitter.js
index dba976f..0d40b82 100644
--- a/test/services/twitter.js
+++ b/test/services/twitter.js
@@ -180,4 +180,4 @@ describe("Twitter Personal Consumer", function() {
             });
         });
     });
-});
\ No newline at end of file
+});