diff --git a/absolutify.js b/absolutify.js
index 1f4bfd1..6608590 100644
--- a/absolutify.js
+++ b/absolutify.js
@@ -9,9 +9,11 @@
  * @return {String} replaced html source
  */
 
-function replace(str, url) {
-  if (typeof url === 'function') return replace.iterate(str, url)
-  return str.replace(replace.rx, '$1' + url + '/$4')
+function absolutify(str, url) {
+  if (typeof url === 'function') return absolutify.iterate(str, url)
+  return str
+    .replace(absolutify.rx, '$1' + url + '/$6')      // Inject the URL into the attribute
+    .replace(new RegExp(url + '//', 'g'), url + '/') // Fix `attr="/"` edgecase causing a `//` issue
 }
 
 /*!
@@ -19,15 +21,15 @@ function replace(str, url) {
  * ensure that the leading `/` of the url is not captured
  *
  * HTML attribute list from: http://stackoverflow.com/questions/2725156/complete-list-of-html-tag-attributes-which-have-a-url-value
- */
-
-replace.rx = /((href|src|codebase|cite|background|cite|action|profile|formaction|icon|manifest|archive)=["'])(([.]+\/)|(?:\/)|(?=#))(?!\/)/g
 
-/*!
- * Match the same as above, but capture the full URL for iteration
+   1. find any possible element containing a url: `prop="`
+   2. ignore leading protocols: `prop="http:`
+   3. ignore protocol skips `prop="//`
+   4. find and omit leading slash to normalize: `prop="/url`
+   5.
  */
 
-replace.captureRx = /((href|src|codebase|cite|background|cite|action|profile|formaction|icon|manifest|archive)=["'])((([.]+\/)|(?:\/)|(?:#))(?!\/)[a-zA-Z0-9._-]+)/g
+absolutify.rx = /((href|src|codebase|cite|background|action|profile|formaction|icon|manifest|archive)=["'])(?!(http|https|ftp|file|filesystem|gopher|ws|wss|about|blob|data|mailto):|(\/\/))((?:\/)?([^'"]+))/g // jshint ignore:line
 
 /**
  * URL replacement using function iteration, this is handled slightly
@@ -39,9 +41,15 @@ replace.captureRx = /((href|src|codebase|cite|background|cite|action|profile|for
  * @return {String} replaced html source
  */
 
-replace.iterate = function(str, iterator) {
-  return str.replace(replace.captureRx, function(full, prefix, prop, url) {
-    return prefix + iterator(url, prop)
+absolutify.iterate = function(str, iterator) {
+  return str.replace(absolutify.rx, function() {
+    var url = arguments[6]
+
+    return arguments[1] + iterator(
+      url === '/' ? '' : url // URL without leading `/` (check for `attr="/"` edgecase)
+    , arguments[2]           // HTML attribute
+    , arguments[5]           // Contains leading `/` if found
+    )
   })
 }
 
@@ -49,7 +57,7 @@ replace.iterate = function(str, iterator) {
  * Exports
  */
 
-if (typeof exports !== 'undefined') module.exports = replace
-else this.absolutify = replace
+if (typeof exports !== 'undefined') module.exports = absolutify
+else this.absolutify = absolutify
 
 }.call(this));
diff --git a/test.js b/test.js
index 7f377d6..cccce14 100644
--- a/test.js
+++ b/test.js
@@ -7,120 +7,297 @@ describe('absolutify', function() {
 
   // Non-changing string, should not get replaced
   var ok = ''
-    + '<img src="www.foo.com" />'
-    + '<img src="google.com" />'
+    + '<a href="ftp://www.foo.com" />'
+    + '<a href="mailto:hello@google.com" />'
     + '<img src="http://www.bar.com" />'
     + '<img src="//baz.com" />'
+    + '<a href="file:///Users/home/file.txt" />'
+    + '<img src="data:image/gif;base64,R0lGODlhEAAQAMQAAORHHOVSKudfOulrSOp3WOyDZu6QdvCch" />'
 
-  it('string replace', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="/relative">Heyo</a>' + ok
-      , 'http://www.example.com'
+  describe('string replace', function() {
+    it('ignores valid values', function() {
+      assert.strictEqual(
+        absolutify(ok, 'http://www.example.com')
+      , ok
       )
-    , '<a href="http://www.example.com/relative">Heyo</a>' + ok
-    )
+    })
 
-    assert.strictEqual(
-      absolutify(
-        '<a href="../relative">Heyo</a>' + ok
-      , 'http://www.example.com'
+    it('/url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/relative">Heyo</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/relative">Heyo</a>'
       )
-    , '<a href="http://www.example.com/../relative">Heyo</a>' + ok
-    )
+  })
 
-    assert.strictEqual(
-      absolutify(
-        '<a href="/">Heyo</a>' + ok
-      , 'http://www.example.com'
+  it('../url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="../relative">Heyo</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/../relative">Heyo</a>'
       )
-    , '<a href="http://www.example.com/">Heyo</a>' + ok
-    )
-  })
+    })
 
-  it('string replace single quote', function() {
-    assert.strictEqual(
-      absolutify(
-        "<a href='../relative'>Heyo</a>" + ok
-      , 'http://www.example.com'
+    it('/', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/">Heyo</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/">Heyo</a>'
       )
-    , "<a href='http://www.example.com/../relative'>Heyo</a>" + ok
-    )
-  })
+    })
 
-  it('string multi-replace', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="/relative">Heyo</a><form action="/index.php">' + ok
-      , 'http://www.example.com'
+    it(':port/url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/index.php">Section</a>'
+        , 'http://www.example.com:80'
+        )
+      , '<a href="http://www.example.com:80/index.php">Section</a>'
       )
-    , '<a href="http://www.example.com/relative">Heyo</a><form action="http://www.example.com/index.php">' + ok
-    )
-  })
+    })
 
-  it('string replace anchor', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="#section">Section</a>' + ok
-      , 'http://www.example.com'
+    it('#anchor', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="#section">Section</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/#section">Section</a>'
       )
-    , '<a href="http://www.example.com/#section">Section</a>' + ok
-    )
-  })
+    })
 
-  it('function replace', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="/relative">Heyo</a>' + ok
-      , function(url, attr) {
-          return 'http://www.example.com' + url
-        }
-      )
-    , '<a href="http://www.example.com/relative">Heyo</a>' + ok
-    )
-
-    assert.strictEqual(
-      absolutify(
-        '<a href="../two">Heyo</a>' + ok
-      , function(url, attr) {
-          return 'http://www.example.com/public/' + url
-        }
-      )
-    , '<a href="http://www.example.com/public/../two">Heyo</a>' + ok
-    )
-
-    assert.strictEqual(
-      absolutify(
-        '<a href="./three">Heyo</a>' + ok
-      , function(url, attr) {
-          return 'http://www.example.com/' + url
-        }
-      )
-    , '<a href="http://www.example.com/./three">Heyo</a>' + ok
-    )
-  })
+    it('url.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="index.php">Section</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/index.php">Section</a>'
+      )
+    })
 
-  it('function replace anchor', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="#section">Section</a>' + ok
-      , function(url, attr) {
-          return 'http://www.example.com' + url
-        }
+    it('url/dir/file.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="nested/dir/index.php">Section</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/nested/dir/index.php">Section</a>'
+      )
+    })
+
+    it('mailto.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="mailtofoobar.ico">Section</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/mailtofoobar.ico">Section</a>'
+      )
+    })
+
+    it('file.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="file.php">Section</a>'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/file.php">Section</a>'
+      )
+    })
+
+    it('../url (quote test)', function() {
+      assert.strictEqual(
+        absolutify(
+          "<a href='../relative'>Heyo</a>"
+        , 'http://www.example.com'
+        )
+      , "<a href='http://www.example.com/../relative'>Heyo</a>"
       )
-    , '<a href="http://www.example.com#section">Section</a>' + ok
-    )
+    })
+
+    it('multi-replace', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/relative">Heyo</a><form action="/index.php">'
+        , 'http://www.example.com'
+        )
+      , '<a href="http://www.example.com/relative">Heyo</a><form action="http://www.example.com/index.php">'
+      )
+    })
+
+    it('/url?querystring[]=val', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a archive="/relative?foo[]=bar&cat=meow">Heyo</a>'
+        , 'http://www.example.com'
+        )
+      , '<a archive="http://www.example.com/relative?foo[]=bar&cat=meow">Heyo</a>'
+      )
+    })
   })
 
-  it('function multi-replace', function() {
-    assert.strictEqual(
-      absolutify(
-        '<a href="/relative">Heyo</a><form action="/index.php">' + ok
-      , function(url, attr) {
+  describe('function replace', function() {
+    it('ignores valid urls', function() {
+      assert.strictEqual(
+        absolutify(ok, function(url, attr) {
           return 'http://www.example.com' + url
-        }
+        })
+      , ok
+      )
+    })
+
+    it('/url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a profile="/relative">Heyo</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, 'relative')
+            assert.strictEqual(attr, 'profile')
+            assert.strictEqual(full, '/relative')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a profile="http://www.example.com/relative">Heyo</a>'
+      )
+    })
+
+    it('/url?querystring[]=val', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a archive="/relative?foo[]=bar&cat=meow">Heyo</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, 'relative?foo[]=bar&cat=meow')
+            assert.strictEqual(attr, 'archive')
+            assert.strictEqual(full, '/relative?foo[]=bar&cat=meow')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a archive="http://www.example.com/relative?foo[]=bar&cat=meow">Heyo</a>'
+      )
+    })
+
+    it('/', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a profile="/">Heyo</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, '')
+            assert.strictEqual(attr, 'profile')
+            assert.strictEqual(full, '/')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a profile="http://www.example.com/">Heyo</a>'
+      )
+    })
+
+    it('../url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<img src="../two">'
+        , function(url, attr) {
+            assert.strictEqual(url, '../two')
+            assert.strictEqual(attr, 'src')
+            return 'http://www.example.com/public/' + url
+          }
+        )
+      , '<img src="http://www.example.com/public/../two">'
+      )
+    })
+
+    it('./url', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="./three">Heyo</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, './three')
+            assert.strictEqual(full, './three')
+            assert.strictEqual(attr, 'href')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a href="http://www.example.com/./three">Heyo</a>'
+      )
+    })
+
+    it('#anchor', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="#section">Section</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, '#section')
+            assert.strictEqual(full, '#section')
+            assert.strictEqual(attr, 'href')
+            return 'http://www.example.com' + url
+          }
+        )
+      , '<a href="http://www.example.com#section">Section</a>'
+      )
+    })
+
+    it('url.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="index.php">Section</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, 'index.php')
+            assert.strictEqual(full, 'index.php')
+            assert.strictEqual(attr, 'href')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a href="http://www.example.com/index.php">Section</a>'
+      )
+    })
+
+    it('/url.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/index.php">Section</a>'
+        , function(url, attr, full) {
+            assert.strictEqual(url, 'index.php')
+            assert.strictEqual(full, '/index.php')
+            assert.strictEqual(attr, 'href')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a href="http://www.example.com/index.php">Section</a>'
+      )
+    })
+
+    it('url/dir/file.ext', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="nested/dir/index.php">Section</a>'
+        , function(url, attr) {
+            assert.strictEqual(url, 'nested/dir/index.php')
+            assert.strictEqual(attr, 'href')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a href="http://www.example.com/nested/dir/index.php">Section</a>'
+      )
+    })
+
+    it('multi-replace', function() {
+      assert.strictEqual(
+        absolutify(
+          '<a href="/relative">Heyo</a><form action="/index.php">'
+        , function(url, attr) {
+            // assert.strictEqual(url, '/relative')
+            // assert.strictEqual(attr, 'href')
+            return 'http://www.example.com/' + url
+          }
+        )
+      , '<a href="http://www.example.com/relative">Heyo</a><form action="http://www.example.com/index.php">'
       )
-    , '<a href="http://www.example.com/relative">Heyo</a><form action="http://www.example.com/index.php">' + ok
-    )
+    })
   })
 })