diff --git a/src/browser/URL.zig b/src/browser/URL.zig
index 4a399a3b..7a3547c2 100644
--- a/src/browser/URL.zig
+++ b/src/browser/URL.zig
@@ -128,7 +128,7 @@ fn isNullTerminated(comptime value: type) bool {
 }
 
 pub fn isCompleteHTTPUrl(url: []const u8) bool {
-    if (url.len < 6) {
+    if (url.len < 3) { // Minimum is "x://"
         return false;
     }
 
@@ -137,9 +137,32 @@ pub fn isCompleteHTTPUrl(url: []const u8) bool {
         return false;
     }
 
-    return std.ascii.startsWithIgnoreCase(url, "https://") or
-        std.ascii.startsWithIgnoreCase(url, "http://") or
-        std.ascii.startsWithIgnoreCase(url, "ftp://");
+    // Check if there's a scheme (protocol) ending with ://
+    const colon_pos = std.mem.indexOfScalar(u8, url, ':') orelse return false;
+
+    // Check if it's followed by //
+    if (colon_pos + 2 >= url.len or url[colon_pos + 1] != '/' or url[colon_pos + 2] != '/') {
+        return false;
+    }
+
+    // Validate that everything before the colon is a valid scheme
+    // A scheme must start with a letter and contain only letters, digits, +, -, .
+    if (colon_pos == 0) {
+        return false;
+    }
+
+    const scheme = url[0..colon_pos];
+    if (!std.ascii.isAlphabetic(scheme[0])) {
+        return false;
+    }
+
+    for (scheme[1..]) |c| {
+        if (!std.ascii.isAlphanumeric(c) and c != '+' and c != '-' and c != '.') {
+            return false;
+        }
+    }
+
+    return true;
 }
 
 pub fn getUsername(raw: [:0]const u8) []const u8 {
@@ -278,6 +301,139 @@ pub fn eqlDocument(first: [:0]const u8, second: [:0]const u8) bool {
     return std.mem.eql(u8, first[0..first_hash_index], second[0..second_hash_index]);
 }
 
+// Helper function to build a URL from components
+pub fn buildUrl(
+    allocator: Allocator,
+    protocol: []const u8,
+    host: []const u8,
+    pathname: []const u8,
+    search: []const u8,
+    hash: []const u8,
+) ![:0]const u8 {
+    return std.fmt.allocPrintSentinel(allocator, "{s}//{s}{s}{s}{s}", .{
+        protocol,
+        host,
+        pathname,
+        search,
+        hash,
+    }, 0);
+}
+
+pub fn setProtocol(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const host = getHost(current);
+    const pathname = getPathname(current);
+    const search = getSearch(current);
+    const hash = getHash(current);
+
+    // Add : suffix if not present
+    const protocol = if (value.len > 0 and value[value.len - 1] != ':')
+        try std.fmt.allocPrint(allocator, "{s}:", .{value})
+    else
+        value;
+
+    return buildUrl(allocator, protocol, host, pathname, search, hash);
+}
+
+pub fn setHost(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const protocol = getProtocol(current);
+    const pathname = getPathname(current);
+    const search = getSearch(current);
+    const hash = getHash(current);
+
+    // Check if the host includes a port
+    const colon_pos = std.mem.lastIndexOfScalar(u8, value, ':');
+    const clean_host = if (colon_pos) |pos| blk: {
+        const port_str = value[pos + 1 ..];
+        // Remove default ports
+        if (std.mem.eql(u8, protocol, "https:") and std.mem.eql(u8, port_str, "443")) {
+            break :blk value[0..pos];
+        }
+        if (std.mem.eql(u8, protocol, "http:") and std.mem.eql(u8, port_str, "80")) {
+            break :blk value[0..pos];
+        }
+        break :blk value;
+    } else value;
+
+    return buildUrl(allocator, protocol, clean_host, pathname, search, hash);
+}
+
+pub fn setHostname(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const current_port = getPort(current);
+    const new_host = if (current_port.len > 0)
+        try std.fmt.allocPrint(allocator, "{s}:{s}", .{ value, current_port })
+    else
+        value;
+
+    return setHost(current, new_host, allocator);
+}
+
+pub fn setPort(current: [:0]const u8, value: ?[]const u8, allocator: Allocator) ![:0]const u8 {
+    const hostname = getHostname(current);
+    const protocol = getProtocol(current);
+
+    // Handle null or default ports
+    const new_host = if (value) |port_str| blk: {
+        if (port_str.len == 0) {
+            break :blk hostname;
+        }
+        // Check if this is a default port for the protocol
+        if (std.mem.eql(u8, protocol, "https:") and std.mem.eql(u8, port_str, "443")) {
+            break :blk hostname;
+        }
+        if (std.mem.eql(u8, protocol, "http:") and std.mem.eql(u8, port_str, "80")) {
+            break :blk hostname;
+        }
+        break :blk try std.fmt.allocPrint(allocator, "{s}:{s}", .{ hostname, port_str });
+    } else hostname;
+
+    return setHost(current, new_host, allocator);
+}
+
+pub fn setPathname(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const protocol = getProtocol(current);
+    const host = getHost(current);
+    const search = getSearch(current);
+    const hash = getHash(current);
+
+    // Add / prefix if not present and value is not empty
+    const pathname = if (value.len > 0 and value[0] != '/')
+        try std.fmt.allocPrint(allocator, "/{s}", .{value})
+    else
+        value;
+
+    return buildUrl(allocator, protocol, host, pathname, search, hash);
+}
+
+pub fn setSearch(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const protocol = getProtocol(current);
+    const host = getHost(current);
+    const pathname = getPathname(current);
+    const hash = getHash(current);
+
+    // Add ? prefix if not present and value is not empty
+    const search = if (value.len > 0 and value[0] != '?')
+        try std.fmt.allocPrint(allocator, "?{s}", .{value})
+    else
+        value;
+
+    return buildUrl(allocator, protocol, host, pathname, search, hash);
+}
+
+pub fn setHash(current: [:0]const u8, value: []const u8, allocator: Allocator) ![:0]const u8 {
+    const protocol = getProtocol(current);
+    const host = getHost(current);
+    const pathname = getPathname(current);
+    const search = getSearch(current);
+
+    // Add # prefix if not present and value is not empty
+    const hash = if (value.len > 0 and value[0] != '#')
+        try std.fmt.allocPrint(allocator, "#{s}", .{value})
+    else
+        value;
+
+    return buildUrl(allocator, protocol, host, pathname, search, hash);
+}
+
 const KnownProtocol = enum {
     @"http:",
     @"https:",
diff --git a/src/browser/tests/legacy/url/url.html b/src/browser/tests/legacy/url/url.html
index ef770e46..72ca45f0 100644
--- a/src/browser/tests/legacy/url/url.html
+++ b/src/browser/tests/legacy/url/url.html
@@ -31,14 +31,14 @@
 </script>
 
 <script id="constructor">
-  testing.expectError("TypeError: invalid argument", () => {
+  testing.expectError("Error: TypeError", () => {
     new URL(document.createElement('a'));
   });
 
   let a = document.createElement('a');
   a.href = 'https://www.lightpanda.io/over?9000=!!';
   const url3 = new URL(a);
-  testing.expectEqual("https://www.lightpanda.io/over?9000=%21%21", url3.href);
+  testing.expectEqual("https://www.lightpanda.io/over?9000=!!", url3.href);
  </script>
 
 <script id=searchParams>
@@ -53,10 +53,10 @@
   testing.expectEqual(3, url.searchParams.size);
 
   // search is dynamic
-  testing.expectEqual("?a=~&b=~&c=foo", url.search);
+  testing.expectEqual("?a=%7E&b=%7E&c=foo", url.search);
 
   // href is dynamic
-  testing.expectEqual("https://foo.bar/path?a=~&b=~&c=foo#fragment", url.href);
+  testing.expectEqual("https://foo.bar/path?a=%7E&b=%7E&c=foo#fragment", url.href);
 
   url.searchParams.delete('c', 'foo');
   testing.expectEqual(null, url.searchParams.get('c'));
@@ -95,7 +95,7 @@
 </script>
 
 <script id=invalidUrl>
-  testing.expectError("Error: Invalid", () => {
+  testing.expectError("Error: TypeError", () => {
     _ = new URL("://foo.bar/path?query#fragment");
   });
 </script>
diff --git a/src/browser/tests/url.html b/src/browser/tests/url.html
index 7faefc32..80b70823 100644
--- a/src/browser/tests/url.html
+++ b/src/browser/tests/url.html
@@ -313,6 +313,23 @@
     url.searchParams.delete('b');
     testing.expectEqual('https://example.com/path', url.href);
   }
+
+  {
+    let url = new URL("https://foo.bar");
+    const searchParams = url.searchParams;
+
+    // SearchParams should be empty.
+    testing.expectEqual(0, searchParams.size);
+
+    url.href = "https://lightpanda.io?over=9000&light=panda";
+    // It won't hurt to check href and host too.
+    testing.expectEqual("https://lightpanda.io/?over=9000&light=panda", url.href);
+    testing.expectEqual("lightpanda.io", url.host);
+    // SearchParams should be updated too when URL is set.
+    testing.expectEqual(2, searchParams.size);
+    testing.expectEqual("9000", searchParams.get("over"));
+    testing.expectEqual("panda", searchParams.get("light"));
+  }
 </script>
 
 <script id=stringifier>
@@ -362,3 +379,280 @@
   testing.expectEqual('https://example.com/base/relative', url.href);
 }
 </script>
+
+<script id=setters>
+{
+  const url = new URL('https://example.com/path');
+  url.href = 'https://newdomain.com/newpath';
+  testing.expectEqual('https://newdomain.com/newpath', url.href);
+  testing.expectEqual('newdomain.com', url.hostname);
+  testing.expectEqual('/newpath', url.pathname);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b#hash');
+  url.href = 'http://other.com/';
+  testing.expectEqual('http://other.com/', url.href);
+  testing.expectEqual('', url.search);
+  testing.expectEqual('', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.protocol = 'http';
+  testing.expectEqual('http://example.com/path', url.href);
+  testing.expectEqual('http:', url.protocol);
+}
+
+{
+  const url = new URL('http://example.com/path');
+  url.protocol = 'https:';
+  testing.expectEqual('https://example.com/path', url.href);
+  testing.expectEqual('https:', url.protocol);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.hostname = 'newhost.com';
+  testing.expectEqual('https://newhost.com/path', url.href);
+  testing.expectEqual('newhost.com', url.hostname);
+}
+
+{
+  const url = new URL('https://example.com:8080/path');
+  url.hostname = 'newhost.com';
+  testing.expectEqual('https://newhost.com:8080/path', url.href);
+  testing.expectEqual('newhost.com', url.hostname);
+  testing.expectEqual('8080', url.port);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.host = 'newhost.com:9000';
+  testing.expectEqual('https://newhost.com:9000/path', url.href);
+  testing.expectEqual('newhost.com', url.hostname);
+  testing.expectEqual('9000', url.port);
+}
+
+{
+  const url = new URL('https://example.com:8080/path');
+  url.host = 'newhost.com';
+  testing.expectEqual('https://newhost.com/path', url.href);
+  testing.expectEqual('newhost.com', url.hostname);
+  testing.expectEqual('', url.port);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.port = '8080';
+  testing.expectEqual('https://example.com:8080/path', url.href);
+  testing.expectEqual('8080', url.port);
+}
+
+{
+  const url = new URL('https://example.com:8080/path');
+  url.port = '';
+  testing.expectEqual('https://example.com/path', url.href);
+  testing.expectEqual('', url.port);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.port = '443';
+  testing.expectEqual('https://example.com/path', url.href);
+  testing.expectEqual('', url.port);
+}
+
+{
+  const url = new URL('http://example.com/path');
+  url.port = '80';
+  testing.expectEqual('http://example.com/path', url.href);
+  testing.expectEqual('', url.port);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.pathname = '/newpath';
+  testing.expectEqual('https://example.com/newpath', url.href);
+  testing.expectEqual('/newpath', url.pathname);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.pathname = 'newpath';
+  testing.expectEqual('https://example.com/newpath', url.href);
+  testing.expectEqual('/newpath', url.pathname);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b#hash');
+  url.pathname = '/new/path';
+  testing.expectEqual('https://example.com/new/path?a=b#hash', url.href);
+  testing.expectEqual('/new/path', url.pathname);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.search = '?a=b';
+  testing.expectEqual('https://example.com/path?a=b', url.href);
+  testing.expectEqual('?a=b', url.search);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.search = 'a=b';
+  testing.expectEqual('https://example.com/path?a=b', url.href);
+  testing.expectEqual('?a=b', url.search);
+}
+
+{
+  const url = new URL('https://example.com/path?old=value');
+  url.search = 'new=value';
+  testing.expectEqual('https://example.com/path?new=value', url.href);
+  testing.expectEqual('?new=value', url.search);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b#hash');
+  url.search = 'c=d';
+  testing.expectEqual('https://example.com/path?c=d#hash', url.href);
+  testing.expectEqual('?c=d', url.search);
+  testing.expectEqual('#hash', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.hash = '#section';
+  testing.expectEqual('https://example.com/path#section', url.href);
+  testing.expectEqual('#section', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path');
+  url.hash = 'section';
+  testing.expectEqual('https://example.com/path#section', url.href);
+  testing.expectEqual('#section', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path#old');
+  url.hash = 'new';
+  testing.expectEqual('https://example.com/path#new', url.href);
+  testing.expectEqual('#new', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b#hash');
+  url.hash = 'newhash';
+  testing.expectEqual('https://example.com/path?a=b#newhash', url.href);
+  testing.expectEqual('?a=b', url.search);
+  testing.expectEqual('#newhash', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path#hash');
+  url.hash = '';
+  testing.expectEqual('https://example.com/path', url.href);
+  testing.expectEqual('', url.hash);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b');
+  url.search = '';
+  testing.expectEqual('https://example.com/path', url.href);
+  testing.expectEqual('', url.search);
+}
+
+{
+  const url = new URL('https://example.com/path?a=b');
+  const sp = url.searchParams;
+  testing.expectEqual('b', sp.get('a'));
+  url.search = 'c=d';
+
+  testing.expectEqual('d', url.searchParams.get('c'));
+  testing.expectEqual(null, url.searchParams.get('a'));
+}
+
+{
+  const url = new URL('https://example.com/path?a=b');
+  const sp = url.searchParams;
+  testing.expectEqual('b', sp.get('a'));
+  url.href = 'https://example.com/other?x=y';
+
+  testing.expectEqual('y', url.searchParams.get('x'));
+  testing.expectEqual(null, url.searchParams.get('a'));
+}
+</script>
+
+<script id=canParse>
+{
+  testing.expectEqual('function', typeof URL.canParse);
+}
+
+{
+  testing.expectEqual(true, URL.canParse('https://example.com'));
+  testing.expectEqual(true, URL.canParse('http://example.com/path'));
+  testing.expectEqual(true, URL.canParse('https://example.com:8080/path?a=b#hash'));
+  testing.expectEqual(true, URL.canParse('ftp://example.com'));
+}
+
+{
+  testing.expectEqual(false, URL.canParse(''));
+  testing.expectEqual(false, URL.canParse('foo.js'));
+  testing.expectEqual(false, URL.canParse('/path/to/file'));
+  testing.expectEqual(false, URL.canParse('?query=value'));
+  testing.expectEqual(false, URL.canParse('#fragment'));
+}
+
+{
+  testing.expectEqual(true, URL.canParse('subpath', 'http://example.com/path/'));
+  testing.expectEqual(true, URL.canParse('/newpath', 'http://example.com/path'));
+  testing.expectEqual(true, URL.canParse('?a=b', 'http://example.com/path'));
+  testing.expectEqual(true, URL.canParse('#hash', 'http://example.com/path'));
+  testing.expectEqual(true, URL.canParse('../foo', 'http://example.com/a/b/c'));
+}
+
+{
+  testing.expectEqual(false, URL.canParse('foo.js', undefined));
+  testing.expectEqual(false, URL.canParse('subpath', undefined));
+  testing.expectEqual(false, URL.canParse('../foo', undefined));
+}
+
+{
+  testing.expectEqual(false, URL.canParse('foo.js', 'not a url'));
+  testing.expectEqual(false, URL.canParse('foo.js', 'bar/baz'));
+  testing.expectEqual(false, URL.canParse('subpath', 'relative/path'));
+}
+
+{
+  testing.expectEqual(false, URL.canParse('http://example.com/absolute', 'invalid base'));
+  testing.expectEqual(false, URL.canParse('https://example.com/path', 'not-a-url'));
+}
+
+{
+  testing.expectEqual(false, URL.canParse('http://example.com', ''));
+  testing.expectEqual(false, URL.canParse('http://example.com', 'relative'));
+}
+
+{
+  testing.expectEqual(true, URL.canParse('http://example.com/absolute', 'http://base.com'));
+  testing.expectEqual(true, URL.canParse('https://example.com/path', 'https://other.com'));
+}
+</script>
+
+<script id=query_encode>
+  {
+    let url = new URL('https://foo.bar/path?a=~&b=%7E#fragment');
+    testing.expectEqual("~", url.searchParams.get('a'));
+    testing.expectEqual("~", url.searchParams.get('b'));
+
+    url.searchParams.append('c', 'foo');
+    testing.expectEqual("foo", url.searchParams.get('c'));
+    testing.expectEqual(1, url.searchParams.getAll('c').length);
+    testing.expectEqual("foo", url.searchParams.getAll('c')[0]);
+    testing.expectEqual(3, url.searchParams.size);
+
+    // search is dynamic
+    testing.expectEqual("?a=%7E&b=%7E&c=foo", url.search);
+  }
+</script>
diff --git a/src/browser/webapi/Location.zig b/src/browser/webapi/Location.zig
index c2c2b1a8..87d0c282 100644
--- a/src/browser/webapi/Location.zig
+++ b/src/browser/webapi/Location.zig
@@ -57,8 +57,8 @@ pub fn getOrigin(self: *const Location, page: *const Page) ![]const u8 {
     return self._url.getOrigin(page);
 }
 
-pub fn getSearch(self: *const Location) []const u8 {
-    return self._url.getSearch();
+pub fn getSearch(self: *const Location, page: *const Page) ![]const u8 {
+    return self._url.getSearch(page);
 }
 
 pub fn getHash(self: *const Location) []const u8 {
diff --git a/src/browser/webapi/URL.zig b/src/browser/webapi/URL.zig
index 49c03b1d..766bd3c2 100644
--- a/src/browser/webapi/URL.zig
+++ b/src/browser/webapi/URL.zig
@@ -35,6 +35,23 @@ _search_params: ?*URLSearchParams = null,
 pub const resolve = @import("../URL.zig").resolve;
 pub const eqlDocument = @import("../URL.zig").eqlDocument;
 
+pub fn canParse(url: []const u8, base_: ?[]const u8, page: *Page) bool {
+    _ = page;
+    const url_is_absolute = U.isCompleteHTTPUrl(url);
+
+    if (base_) |b| {
+        // Base must be valid even if URL is absolute
+        if (!U.isCompleteHTTPUrl(b)) {
+            return false;
+        }
+        return true;
+    } else if (!url_is_absolute) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
 pub fn init(url: [:0]const u8, base_: ?[:0]const u8, page: *Page) !*URL {
     const url_is_absolute = @import("../URL.zig").isCompleteHTTPUrl(url);
 
@@ -96,7 +113,17 @@ pub fn getOrigin(self: *const URL, page: *const Page) ![]const u8 {
     };
 }
 
-pub fn getSearch(self: *const URL) []const u8 {
+pub fn getSearch(self: *const URL, page: *const Page) ![]const u8 {
+    // If searchParams has been accessed, generate search from it
+    if (self._search_params) |sp| {
+        if (sp.getSize() == 0) {
+            return "";
+        }
+        var buf = std.Io.Writer.Allocating.init(page.call_arena);
+        try buf.writer.writeByte('?');
+        try sp.toString(&buf.writer);
+        return buf.written();
+    }
     return U.getSearch(self._raw);
 }
 
@@ -110,7 +137,7 @@ pub fn getSearchParams(self: *URL, page: *Page) !*URLSearchParams {
     }
 
     // Get current search string (without the '?')
-    const search = self.getSearch();
+    const search = try self.getSearch(page);
     const search_value = if (search.len > 0) search[1..] else "";
 
     const params = try URLSearchParams.init(.{ .query_string = search_value }, page);
@@ -118,6 +145,61 @@ pub fn getSearchParams(self: *URL, page: *Page) !*URLSearchParams {
     return params;
 }
 
+pub fn setHref(self: *URL, value: []const u8, page: *Page) !void {
+    const base = if (U.isCompleteHTTPUrl(value)) page.url else self._raw;
+    const raw = try U.resolve(self._arena orelse page.arena, base, value, .{ .always_dupe = true });
+    self._raw = raw;
+
+    // Update existing searchParams if it exists
+    if (self._search_params) |sp| {
+        const search = U.getSearch(raw);
+        const search_value = if (search.len > 0) search[1..] else "";
+        try sp.updateFromString(search_value, page);
+    }
+}
+
+pub fn setProtocol(self: *URL, value: []const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setProtocol(self._raw, value, allocator);
+}
+
+pub fn setHost(self: *URL, value: []const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setHost(self._raw, value, allocator);
+}
+
+pub fn setHostname(self: *URL, value: []const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setHostname(self._raw, value, allocator);
+}
+
+pub fn setPort(self: *URL, value: ?[]const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setPort(self._raw, value, allocator);
+}
+
+pub fn setPathname(self: *URL, value: []const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setPathname(self._raw, value, allocator);
+}
+
+pub fn setSearch(self: *URL, value: []const u8, page: *Page) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setSearch(self._raw, value, allocator);
+
+    // Update existing searchParams if it exists
+    if (self._search_params) |sp| {
+        const search = U.getSearch(self._raw);
+        const search_value = if (search.len > 0) search[1..] else "";
+        try sp.updateFromString(search_value, page);
+    }
+}
+
+pub fn setHash(self: *URL, value: []const u8) !void {
+    const allocator = self._arena orelse return error.NoAllocator;
+    self._raw = try U.setHash(self._raw, value, allocator);
+}
+
 pub fn toString(self: *const URL, page: *const Page) ![:0]const u8 {
     const sp = self._search_params orelse {
         return self._raw;
@@ -137,6 +219,13 @@ pub fn toString(self: *const URL, page: *const Page) ![:0]const u8 {
     var buf = std.Io.Writer.Allocating.init(page.call_arena);
     try buf.writer.writeAll(base);
 
+    // Add / if missing (e.g., "https://example.com" -> "https://example.com/")
+    // Only add if pathname is just "/" and not already in the base
+    const pathname = U.getPathname(raw);
+    if (std.mem.eql(u8, pathname, "/") and !std.mem.endsWith(u8, base, "/")) {
+        try buf.writer.writeByte('/');
+    }
+
     // Only add ? if there are params
     if (sp.getSize() > 0) {
         try buf.writer.writeByte('?');
@@ -159,19 +248,20 @@ pub const JsApi = struct {
     };
 
     pub const constructor = bridge.constructor(URL.init, .{});
+    pub const canParse = bridge.function(URL.canParse, .{ .static = true });
     pub const toString = bridge.function(URL.toString, .{});
     pub const toJSON = bridge.function(URL.toString, .{});
-    pub const href = bridge.accessor(URL.toString, null, .{});
-    pub const search = bridge.accessor(URL.getSearch, null, .{});
-    pub const hash = bridge.accessor(URL.getHash, null, .{});
-    pub const pathname = bridge.accessor(URL.getPathname, null, .{});
+    pub const href = bridge.accessor(URL.toString, URL.setHref, .{});
+    pub const search = bridge.accessor(URL.getSearch, URL.setSearch, .{});
+    pub const hash = bridge.accessor(URL.getHash, URL.setHash, .{});
+    pub const pathname = bridge.accessor(URL.getPathname, URL.setPathname, .{});
     pub const username = bridge.accessor(URL.getUsername, null, .{});
     pub const password = bridge.accessor(URL.getPassword, null, .{});
-    pub const hostname = bridge.accessor(URL.getHostname, null, .{});
-    pub const host = bridge.accessor(URL.getHost, null, .{});
-    pub const port = bridge.accessor(URL.getPort, null, .{});
+    pub const hostname = bridge.accessor(URL.getHostname, URL.setHostname, .{});
+    pub const host = bridge.accessor(URL.getHost, URL.setHost, .{});
+    pub const port = bridge.accessor(URL.getPort, URL.setPort, .{});
     pub const origin = bridge.accessor(URL.getOrigin, null, .{});
-    pub const protocol = bridge.accessor(URL.getProtocol, null, .{});
+    pub const protocol = bridge.accessor(URL.getProtocol, URL.setProtocol, .{});
     pub const searchParams = bridge.accessor(URL.getSearchParams, null, .{});
 };
 
diff --git a/src/browser/webapi/element/html/Anchor.zig b/src/browser/webapi/element/html/Anchor.zig
index 006843db..75e61c20 100644
--- a/src/browser/webapi/element/html/Anchor.zig
+++ b/src/browser/webapi/element/html/Anchor.zig
@@ -84,26 +84,7 @@ pub fn getHost(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setHost(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const protocol = URL.getProtocol(href);
-    const pathname = URL.getPathname(href);
-    const search = URL.getSearch(href);
-    const hash = URL.getHash(href);
-
-    // Check if the host includes a port
-    const colon_pos = std.mem.lastIndexOfScalar(u8, value, ':');
-    const clean_host = if (colon_pos) |pos| blk: {
-        const port_str = value[pos + 1 ..];
-        // Remove default ports
-        if (std.mem.eql(u8, protocol, "https:") and std.mem.eql(u8, port_str, "443")) {
-            break :blk value[0..pos];
-        }
-        if (std.mem.eql(u8, protocol, "http:") and std.mem.eql(u8, port_str, "80")) {
-            break :blk value[0..pos];
-        }
-        break :blk value;
-    } else value;
-
-    const new_href = try buildUrl(page.call_arena, protocol, clean_host, pathname, search, hash);
+    const new_href = try URL.setHost(href, value, page.call_arena);
     try setHref(self, new_href, page);
 }
 
@@ -114,13 +95,8 @@ pub fn getHostname(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setHostname(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const current_port = URL.getPort(href);
-    const new_host = if (current_port.len > 0)
-        try std.fmt.allocPrint(page.call_arena, "{s}:{s}", .{ value, current_port })
-    else
-        value;
-
-    try setHost(self, new_host, page);
+    const new_href = try URL.setHostname(href, value, page.call_arena);
+    try setHref(self, new_href, page);
 }
 
 pub fn getPort(self: *Anchor, page: *Page) ![]const u8 {
@@ -142,25 +118,8 @@ pub fn getPort(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setPort(self: *Anchor, value: ?[]const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const hostname = URL.getHostname(href);
-    const protocol = URL.getProtocol(href);
-
-    // Handle null or default ports
-    const new_host = if (value) |port_str| blk: {
-        if (port_str.len == 0) {
-            break :blk hostname;
-        }
-        // Check if this is a default port for the protocol
-        if (std.mem.eql(u8, protocol, "https:") and std.mem.eql(u8, port_str, "443")) {
-            break :blk hostname;
-        }
-        if (std.mem.eql(u8, protocol, "http:") and std.mem.eql(u8, port_str, "80")) {
-            break :blk hostname;
-        }
-        break :blk try std.fmt.allocPrint(page.call_arena, "{s}:{s}", .{ hostname, port_str });
-    } else hostname;
-
-    try setHost(self, new_host, page);
+    const new_href = try URL.setPort(href, value, page.call_arena);
+    try setHref(self, new_href, page);
 }
 
 pub fn getSearch(self: *Anchor, page: *Page) ![]const u8 {
@@ -170,18 +129,7 @@ pub fn getSearch(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setSearch(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const protocol = URL.getProtocol(href);
-    const host = URL.getHost(href);
-    const pathname = URL.getPathname(href);
-    const hash = URL.getHash(href);
-
-    // Add ? prefix if not present and value is not empty
-    const search = if (value.len > 0 and value[0] != '?')
-        try std.fmt.allocPrint(page.call_arena, "?{s}", .{value})
-    else
-        value;
-
-    const new_href = try buildUrl(page.call_arena, protocol, host, pathname, search, hash);
+    const new_href = try URL.setSearch(href, value, page.call_arena);
     try setHref(self, new_href, page);
 }
 
@@ -192,18 +140,7 @@ pub fn getHash(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setHash(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const protocol = URL.getProtocol(href);
-    const host = URL.getHost(href);
-    const pathname = URL.getPathname(href);
-    const search = URL.getSearch(href);
-
-    // Add # prefix if not present and value is not empty
-    const hash = if (value.len > 0 and value[0] != '#')
-        try std.fmt.allocPrint(page.call_arena, "#{s}", .{value})
-    else
-        value;
-
-    const new_href = try buildUrl(page.call_arena, protocol, host, pathname, search, hash);
+    const new_href = try URL.setHash(href, value, page.call_arena);
     try setHref(self, new_href, page);
 }
 
@@ -214,18 +151,7 @@ pub fn getPathname(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setPathname(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const protocol = URL.getProtocol(href);
-    const host = URL.getHost(href);
-    const search = URL.getSearch(href);
-    const hash = URL.getHash(href);
-
-    // Add / prefix if not present and value is not empty
-    const pathname = if (value.len > 0 and value[0] != '/')
-        try std.fmt.allocPrint(page.call_arena, "/{s}", .{value})
-    else
-        value;
-
-    const new_href = try buildUrl(page.call_arena, protocol, host, pathname, search, hash);
+    const new_href = try URL.setPathname(href, value, page.call_arena);
     try setHref(self, new_href, page);
 }
 
@@ -236,18 +162,7 @@ pub fn getProtocol(self: *Anchor, page: *Page) ![]const u8 {
 
 pub fn setProtocol(self: *Anchor, value: []const u8, page: *Page) !void {
     const href = try getResolvedHref(self, page) orelse return;
-    const host = URL.getHost(href);
-    const pathname = URL.getPathname(href);
-    const search = URL.getSearch(href);
-    const hash = URL.getHash(href);
-
-    // Add : suffix if not present
-    const protocol = if (value.len > 0 and value[value.len - 1] != ':')
-        try std.fmt.allocPrint(page.call_arena, "{s}:", .{value})
-    else
-        value;
-
-    const new_href = try buildUrl(page.call_arena, protocol, host, pathname, search, hash);
+    const new_href = try URL.setProtocol(href, value, page.call_arena);
     try setHref(self, new_href, page);
 }
 
@@ -283,24 +198,6 @@ fn getResolvedHref(self: *Anchor, page: *Page) !?[:0]const u8 {
     return try URL.resolve(page.call_arena, page.url, href, .{});
 }
 
-// Helper function to build a new URL from components
-fn buildUrl(
-    allocator: std.mem.Allocator,
-    protocol: []const u8,
-    host: []const u8,
-    pathname: []const u8,
-    search: []const u8,
-    hash: []const u8,
-) ![:0]const u8 {
-    return std.fmt.allocPrintSentinel(allocator, "{s}//{s}{s}{s}{s}", .{
-        protocol,
-        host,
-        pathname,
-        search,
-        hash,
-    }, 0);
-}
-
 pub const JsApi = struct {
     pub const bridge = js.Bridge(Anchor);
 
diff --git a/src/browser/webapi/net/URLSearchParams.zig b/src/browser/webapi/net/URLSearchParams.zig
index f3069531..2cfe3b2c 100644
--- a/src/browser/webapi/net/URLSearchParams.zig
+++ b/src/browser/webapi/net/URLSearchParams.zig
@@ -61,6 +61,10 @@ pub fn init(opts_: ?InitOpts, page: *Page) !*URLSearchParams {
     });
 }
 
+pub fn updateFromString(self: *URLSearchParams, query_string: []const u8, page: *Page) !void {
+    self._params = try paramsFromString(self._arena, query_string, &page.buf);
+}
+
 pub fn getSize(self: *const URLSearchParams) usize {
     return self._params.len();
 }
@@ -277,7 +281,7 @@ fn escape(input: []const u8, writer: *std.Io.Writer) !void {
 
 fn isUnreserved(c: u8) bool {
     return switch (c) {
-        'A'...'Z', 'a'...'z', '0'...'9', '-', '.', '_', '~' => true,
+        'A'...'Z', 'a'...'z', '0'...'9', '-', '.', '_' => true,
         else => false,
     };
 }