diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index ba1741ba321..ae18f075b0e 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -2019,6 +2019,14 @@ impl ScriptThread {
                     reply,
                 )
             },
+            WebDriverScriptCommand::FindElementTagName(selector, reply) => {
+                webdriver_handlers::handle_find_element_tag_name(
+                    &*documents,
+                    pipeline_id,
+                    selector,
+                    reply,
+                )
+            },
             WebDriverScriptCommand::FindElementsCSS(selector, reply) => {
                 webdriver_handlers::handle_find_elements_css(
                     &*documents,
@@ -2027,6 +2035,14 @@ impl ScriptThread {
                     reply,
                 )
             },
+            WebDriverScriptCommand::FindElementsTagName(selector, reply) => {
+                webdriver_handlers::handle_find_elements_tag_name(
+                    &*documents,
+                    pipeline_id,
+                    selector,
+                    reply,
+                )
+            },
             WebDriverScriptCommand::FindElementElementCSS(selector, element_id, reply) => {
                 webdriver_handlers::handle_find_element_element_css(
                     &*documents,
@@ -2036,6 +2052,15 @@ impl ScriptThread {
                     reply,
                 )
             },
+            WebDriverScriptCommand::FindElementElementTagName(selector, element_id, reply) => {
+                webdriver_handlers::handle_find_element_element_tag_name(
+                    &*documents,
+                    pipeline_id,
+                    element_id,
+                    selector,
+                    reply,
+                )
+            },
             WebDriverScriptCommand::FindElementElementsCSS(selector, element_id, reply) => {
                 webdriver_handlers::handle_find_element_elements_css(
                     &*documents,
@@ -2045,6 +2070,15 @@ impl ScriptThread {
                     reply,
                 )
             },
+            WebDriverScriptCommand::FindElementElementsTagName(selector, element_id, reply) => {
+                webdriver_handlers::handle_find_element_elements_tag_name(
+                    &*documents,
+                    pipeline_id,
+                    element_id,
+                    selector,
+                    reply,
+                )
+            },
             WebDriverScriptCommand::FocusElement(element_id, reply) => {
                 webdriver_handlers::handle_focus_element(
                     &*documents,
diff --git a/components/script/webdriver_handlers.rs b/components/script/webdriver_handlers.rs
index 5574451bd5b..c960878f60d 100644
--- a/components/script/webdriver_handlers.rs
+++ b/components/script/webdriver_handlers.rs
@@ -182,6 +182,25 @@ pub fn handle_find_element_css(
     reply.send(node_id).unwrap();
 }
 
+pub fn handle_find_element_tag_name(
+    documents: &Documents,
+    pipeline: PipelineId,
+    selector: String,
+    reply: IpcSender<Result<Option<String>, ()>>,
+) {
+    let node_id = documents
+        .find_document(pipeline)
+        .ok_or(())
+        .and_then(|doc| {
+            Ok(doc
+                .GetElementsByTagName(DOMString::from(selector))
+                .elements_iter()
+                .next())
+        })
+        .map(|node| node.map(|x| x.upcast::<Node>().unique_id()));
+    reply.send(node_id).unwrap();
+}
+
 pub fn handle_find_elements_css(
     documents: &Documents,
     pipeline: PipelineId,
@@ -204,6 +223,25 @@ pub fn handle_find_elements_css(
     reply.send(node_ids).unwrap();
 }
 
+pub fn handle_find_elements_tag_name(
+    documents: &Documents,
+    pipeline: PipelineId,
+    selector: String,
+    reply: IpcSender<Result<Vec<String>, ()>>,
+) {
+    let node_ids = documents
+        .find_document(pipeline)
+        .ok_or(())
+        .and_then(|doc| Ok(doc.GetElementsByTagName(DOMString::from(selector))))
+        .map(|nodes| {
+            nodes
+                .elements_iter()
+                .map(|x| x.upcast::<Node>().unique_id())
+                .collect::<Vec<String>>()
+        });
+    reply.send(node_ids).unwrap();
+}
+
 pub fn handle_find_element_element_css(
     documents: &Documents,
     pipeline: PipelineId,
@@ -221,12 +259,32 @@ pub fn handle_find_element_element_css(
     reply.send(node_id).unwrap();
 }
 
-pub fn handle_find_element_elements_css(
+pub fn handle_find_element_element_tag_name(
     documents: &Documents,
     pipeline: PipelineId,
     element_id: String,
     selector: String,
     reply: IpcSender<Result<Option<String>, ()>>,
+) {
+    let node_id = find_node_by_unique_id(documents, pipeline, element_id)
+        .ok_or(())
+        .and_then(|node| match node.downcast::<Element>() {
+            Some(elem) => Ok(elem
+                .GetElementsByTagName(DOMString::from(selector))
+                .elements_iter()
+                .next()),
+            None => Err(()),
+        })
+        .map(|node| node.map(|x| x.upcast::<Node>().unique_id()));
+    reply.send(node_id).unwrap();
+}
+
+pub fn handle_find_element_elements_css(
+    documents: &Documents,
+    pipeline: PipelineId,
+    element_id: String,
+    selector: String,
+    reply: IpcSender<Result<Vec<String>, ()>>,
 ) {
     let node_ids = find_node_by_unique_id(documents, pipeline, element_id)
         .ok_or(())
@@ -237,12 +295,34 @@ pub fn handle_find_element_elements_css(
         .map(|nodes| {
             nodes
                 .iter()
-                .map(|x| Some(x.upcast::<Node>().unique_id()))
+                .map(|x| x.upcast::<Node>().unique_id())
                 .collect()
         });
     reply.send(node_ids).unwrap();
 }
 
+pub fn handle_find_element_elements_tag_name(
+    documents: &Documents,
+    pipeline: PipelineId,
+    element_id: String,
+    selector: String,
+    reply: IpcSender<Result<Vec<String>, ()>>,
+) {
+    let node_ids = find_node_by_unique_id(documents, pipeline, element_id)
+        .ok_or(())
+        .and_then(|node| match node.downcast::<Element>() {
+            Some(elem) => Ok(elem.GetElementsByTagName(DOMString::from(selector))),
+            None => Err(()),
+        })
+        .map(|nodes| {
+            nodes
+                .elements_iter()
+                .map(|x| x.upcast::<Node>().unique_id())
+                .collect::<Vec<String>>()
+        });
+    reply.send(node_ids).unwrap();
+}
+
 pub fn handle_focus_element(
     documents: &Documents,
     pipeline: PipelineId,
diff --git a/components/script_traits/webdriver_msg.rs b/components/script_traits/webdriver_msg.rs
index 02a2190f0cd..d0b0357309f 100644
--- a/components/script_traits/webdriver_msg.rs
+++ b/components/script_traits/webdriver_msg.rs
@@ -25,9 +25,13 @@ pub enum WebDriverScriptCommand {
     ExecuteScript(String, IpcSender<WebDriverJSResult>),
     ExecuteAsyncScript(String, IpcSender<WebDriverJSResult>),
     FindElementCSS(String, IpcSender<Result<Option<String>, ()>>),
+    FindElementTagName(String, IpcSender<Result<Option<String>, ()>>),
     FindElementsCSS(String, IpcSender<Result<Vec<String>, ()>>),
+    FindElementsTagName(String, IpcSender<Result<Vec<String>, ()>>),
     FindElementElementCSS(String, String, IpcSender<Result<Option<String>, ()>>),
-    FindElementElementsCSS(String, String, IpcSender<Result<Option<String>, ()>>),
+    FindElementElementTagName(String, String, IpcSender<Result<Option<String>, ()>>),
+    FindElementElementsCSS(String, String, IpcSender<Result<Vec<String>, ()>>),
+    FindElementElementsTagName(String, String, IpcSender<Result<Vec<String>, ()>>),
     FocusElement(String, IpcSender<Result<(), ()>>),
     GetActiveElement(IpcSender<Option<String>>),
     GetCookie(String, IpcSender<Vec<Serde<Cookie<'static>>>>),
diff --git a/components/webdriver_server/lib.rs b/components/webdriver_server/lib.rs
index 4df9e0d56b6..d938a5153fb 100644
--- a/components/webdriver_server/lib.rs
+++ b/components/webdriver_server/lib.rs
@@ -804,17 +804,25 @@ impl Handler {
         &self,
         parameters: &LocatorParameters,
     ) -> WebDriverResult<WebDriverResponse> {
-        if parameters.using != LocatorStrategy::CSSSelector {
-            return Err(WebDriverError::new(
-                ErrorStatus::UnsupportedOperation,
-                "Unsupported locator strategy",
-            ));
-        }
-
         let (sender, receiver) = ipc::channel().unwrap();
 
-        let cmd = WebDriverScriptCommand::FindElementCSS(parameters.value.clone(), sender);
-        self.browsing_context_script_command(cmd)?;
+        match parameters.using {
+            LocatorStrategy::CSSSelector => {
+                let cmd = WebDriverScriptCommand::FindElementCSS(parameters.value.clone(), sender);
+                self.browsing_context_script_command(cmd)?;
+            },
+            LocatorStrategy::TagName => {
+                let cmd =
+                    WebDriverScriptCommand::FindElementTagName(parameters.value.clone(), sender);
+                self.browsing_context_script_command(cmd)?;
+            },
+            _ => {
+                return Err(WebDriverError::new(
+                    ErrorStatus::UnsupportedOperation,
+                    "Unsupported locator strategy",
+                ));
+            },
+        }
 
         match receiver.recv().unwrap() {
             Ok(value) => {
@@ -894,20 +902,31 @@ impl Handler {
         Ok(WebDriverResponse::Void)
     }
 
+    // https://w3c.github.io/webdriver/#find-elements
     fn handle_find_elements(
         &self,
         parameters: &LocatorParameters,
     ) -> WebDriverResult<WebDriverResponse> {
-        if parameters.using != LocatorStrategy::CSSSelector {
-            return Err(WebDriverError::new(
-                ErrorStatus::UnsupportedOperation,
-                "Unsupported locator strategy",
-            ));
+        let (sender, receiver) = ipc::channel().unwrap();
+
+        match parameters.using {
+            LocatorStrategy::CSSSelector => {
+                let cmd = WebDriverScriptCommand::FindElementsCSS(parameters.value.clone(), sender);
+                self.browsing_context_script_command(cmd)?;
+            },
+            LocatorStrategy::TagName => {
+                let cmd =
+                    WebDriverScriptCommand::FindElementsTagName(parameters.value.clone(), sender);
+                self.browsing_context_script_command(cmd)?;
+            },
+            _ => {
+                return Err(WebDriverError::new(
+                    ErrorStatus::UnsupportedOperation,
+                    "Unsupported locator strategy",
+                ));
+            },
         }
 
-        let (sender, receiver) = ipc::channel().unwrap();
-        let cmd = WebDriverScriptCommand::FindElementsCSS(parameters.value.clone(), sender);
-        self.browsing_context_script_command(cmd)?;
         match receiver.recv().unwrap() {
             Ok(value) => {
                 let resp_value: Vec<Value> = value
@@ -931,21 +950,32 @@ impl Handler {
         element: &WebElement,
         parameters: &LocatorParameters,
     ) -> WebDriverResult<WebDriverResponse> {
-        if parameters.using != LocatorStrategy::CSSSelector {
-            return Err(WebDriverError::new(
-                ErrorStatus::UnsupportedOperation,
-                "Unsupported locator strategy",
-            ));
-        }
-
         let (sender, receiver) = ipc::channel().unwrap();
-        let cmd = WebDriverScriptCommand::FindElementElementCSS(
-            parameters.value.clone(),
-            element.id.clone(),
-            sender,
-        );
 
-        self.browsing_context_script_command(cmd)?;
+        match parameters.using {
+            LocatorStrategy::CSSSelector => {
+                let cmd = WebDriverScriptCommand::FindElementElementCSS(
+                    parameters.value.clone(),
+                    element.id.clone(),
+                    sender,
+                );
+                self.browsing_context_script_command(cmd)?;
+            },
+            LocatorStrategy::TagName => {
+                let cmd = WebDriverScriptCommand::FindElementElementTagName(
+                    parameters.value.clone(),
+                    element.id.clone(),
+                    sender,
+                );
+                self.browsing_context_script_command(cmd)?;
+            },
+            _ => {
+                return Err(WebDriverError::new(
+                    ErrorStatus::UnsupportedOperation,
+                    "Unsupported locator strategy",
+                ));
+            },
+        }
 
         match receiver.recv().unwrap() {
             Ok(value) => {
@@ -967,34 +997,46 @@ impl Handler {
         element: &WebElement,
         parameters: &LocatorParameters,
     ) -> WebDriverResult<WebDriverResponse> {
-        if parameters.using != LocatorStrategy::CSSSelector {
-            return Err(WebDriverError::new(
-                ErrorStatus::UnsupportedOperation,
-                "Unsupported locator strategy",
-            ));
-        }
-
         let (sender, receiver) = ipc::channel().unwrap();
-        let cmd = WebDriverScriptCommand::FindElementElementsCSS(
-            parameters.value.clone(),
-            element.id.clone(),
-            sender,
-        );
 
-        self.browsing_context_script_command(cmd)?;
+        match parameters.using {
+            LocatorStrategy::CSSSelector => {
+                let cmd = WebDriverScriptCommand::FindElementElementsCSS(
+                    parameters.value.clone(),
+                    element.id.clone(),
+                    sender,
+                );
+                self.browsing_context_script_command(cmd)?;
+            },
+            LocatorStrategy::TagName => {
+                let cmd = WebDriverScriptCommand::FindElementElementsTagName(
+                    parameters.value.clone(),
+                    element.id.clone(),
+                    sender,
+                );
+                self.browsing_context_script_command(cmd)?;
+            },
+            _ => {
+                return Err(WebDriverError::new(
+                    ErrorStatus::UnsupportedOperation,
+                    "Unsupported locator strategy",
+                ));
+            },
+        }
 
         match receiver.recv().unwrap() {
             Ok(value) => {
-                let value_resp = value
+                let resp_value: Vec<Value> = value
                     .into_iter()
                     .map(|x| serde_json::to_value(WebElement::new(x)).unwrap())
-                    .collect::<Vec<Value>>();
-                let value_resp = serde_json::Value::Array(value_resp);
-                Ok(WebDriverResponse::Generic(ValueResponse(value_resp)))
+                    .collect();
+                Ok(WebDriverResponse::Generic(ValueResponse(
+                    serde_json::to_value(resp_value)?,
+                )))
             },
             Err(_) => Err(WebDriverError::new(
                 ErrorStatus::InvalidSelector,
-                "Invalid Selector",
+                "Invalid selector",
             )),
         }
     }
diff --git a/tests/wpt/metadata/webdriver/tests/find_element/find.py.ini b/tests/wpt/metadata/webdriver/tests/find_element/find.py.ini
index e6839484fca..7bdd2a78362 100644
--- a/tests/wpt/metadata/webdriver/tests/find_element/find.py.ini
+++ b/tests/wpt/metadata/webdriver/tests/find_element/find.py.ini
@@ -11,9 +11,6 @@
   [test_find_element_partial_link_text[<a href=#>&nbsp;partial link text&nbsp;</a>-link\]]
     expected: FAIL
 
-  [test_htmldocument[tag name-html\]]
-    expected: FAIL
-
   [test_find_element_link_text[<a href=#>link<br>text</a>-link\ntext\]]
     expected: FAIL
 
@@ -62,9 +59,6 @@
   [test_find_element_partial_link_text[<a href=#>partial link text</a>-k t\]]
     expected: FAIL
 
-  [test_find_element[tag name-a\]]
-    expected: FAIL
-
   [test_xhtml_namespace[partial link text-link text\]]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webdriver/tests/find_element_from_element/find.py.ini b/tests/wpt/metadata/webdriver/tests/find_element_from_element/find.py.ini
index 98bed60f561..ab4ed4ee7c9 100644
--- a/tests/wpt/metadata/webdriver/tests/find_element_from_element/find.py.ini
+++ b/tests/wpt/metadata/webdriver/tests/find_element_from_element/find.py.ini
@@ -62,9 +62,6 @@
   [test_find_element_partial_link_text[<a href=#>partial link text</a>-k t\]]
     expected: FAIL
 
-  [test_find_element[tag name-a\]]
-    expected: FAIL
-
   [test_xhtml_namespace[partial link text-link text\]]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webdriver/tests/find_elements/find.py.ini b/tests/wpt/metadata/webdriver/tests/find_elements/find.py.ini
index a0a124a2b28..27b11b2d6ad 100644
--- a/tests/wpt/metadata/webdriver/tests/find_elements/find.py.ini
+++ b/tests/wpt/metadata/webdriver/tests/find_elements/find.py.ini
@@ -5,9 +5,6 @@
   [test_find_elements_link_text[<a href=#>LINK TEXT</a>-LINK TEXT\]]
     expected: FAIL
 
-  [test_htmldocument[tag name-html\]]
-    expected: FAIL
-
   [test_find_elements_link_text[<a href=#>link text</a>-link text\]]
     expected: FAIL
 
@@ -50,9 +47,6 @@
   [test_find_elements[xpath-//a\]]
     expected: FAIL
 
-  [test_find_elements[tag name-a\]]
-    expected: FAIL
-
   [test_find_elements_partial_link_text[<a href=# style='text-transform: uppercase'>partial link text</a>-LINK\]]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/webdriver/tests/find_elements_from_element/find.py.ini b/tests/wpt/metadata/webdriver/tests/find_elements_from_element/find.py.ini
index c3100b33708..52f2c179c81 100644
--- a/tests/wpt/metadata/webdriver/tests/find_elements_from_element/find.py.ini
+++ b/tests/wpt/metadata/webdriver/tests/find_elements_from_element/find.py.ini
@@ -44,18 +44,12 @@
   [test_parent_of_document_node_errors]
     expected: FAIL
 
-  [test_no_element[css selector-#wontExist\]]
-    expected: FAIL
-
   [test_find_elements_partial_link_text[<a href=#>partial link&amp;text</a>-k&t\]]
     expected: FAIL
 
   [test_find_elements[xpath-//a\]]
     expected: FAIL
 
-  [test_find_elements[tag name-a\]]
-    expected: FAIL
-
   [test_find_elements_partial_link_text[<a href=# style='text-transform: uppercase'>partial link text</a>-LINK\]]
     expected: FAIL