diff --git a/src/app.zig b/src/app.zig
index f946c52c..14117612 100644
--- a/src/app.zig
+++ b/src/app.zig
@@ -1,7 +1,6 @@
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 
-const js = @import("runtime/js.zig");
 const Loop = @import("runtime/loop.zig").Loop;
 const HttpClient = @import("http/client.zig").Client;
 const Telemetry = @import("telemetry/telemetry.zig").Telemetry;
diff --git a/src/browser/browser.zig b/src/browser/browser.zig
index 3d35b603..9fa31f27 100644
--- a/src/browser/browser.zig
+++ b/src/browser/browser.zig
@@ -36,21 +36,16 @@ const URL = @import("../url.zig").URL;
 
 const http = @import("../http/client.zig");
 const storage = @import("storage/storage.zig");
-const Loop = @import("../runtime/loop.zig").Loop;
 const SessionState = @import("env.zig").SessionState;
-const HttpClient = @import("../http/client.zig").Client;
 const Notification = @import("../notification.zig").Notification;
 
 const polyfill = @import("polyfill/polyfill.zig");
 
 const log = std.log.scoped(.browser);
 
-pub const user_agent = "Lightpanda/1.0";
-
 // Browser is an instance of the browser.
 // You can create multiple browser instances.
 // A browser contains only one session.
-// TODO allow multiple sessions per browser.
 pub const Browser = struct {
     env: *Env,
     app: *App,
@@ -839,12 +834,6 @@ const FlatRenderer = struct {
     }
 };
 
-const NoopContext = struct {
-    pub fn onInspectorResponse(_: *anyopaque, _: u32, _: []const u8) void {}
-    pub fn onInspectorEvent(_: *anyopaque, _: []const u8) void {}
-    pub fn notify(_: *anyopaque, _: *const Notification) !void {}
-};
-
 fn timestamp() u32 {
     const ts = std.posix.clock_gettime(std.posix.CLOCK.MONOTONIC) catch unreachable;
     return @intCast(ts.sec);
diff --git a/src/browser/dom/attribute.zig b/src/browser/dom/attribute.zig
index a8ebc3c2..ece5a2e2 100644
--- a/src/browser/dom/attribute.zig
+++ b/src/browser/dom/attribute.zig
@@ -16,12 +16,9 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 
 const Node = @import("node.zig").Node;
-const DOMException = @import("exceptions.zig").DOMException;
 
 // WEB IDL https://dom.spec.whatwg.org/#attr
 pub const Attr = struct {
diff --git a/src/browser/dom/cdata_section.zig b/src/browser/dom/cdata_section.zig
index 1b3ac6df..484fb82e 100644
--- a/src/browser/dom/cdata_section.zig
+++ b/src/browser/dom/cdata_section.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 
 const Text = @import("text.zig").Text;
diff --git a/src/browser/dom/comment.zig b/src/browser/dom/comment.zig
index 5a7bcce7..5ac9d493 100644
--- a/src/browser/dom/comment.zig
+++ b/src/browser/dom/comment.zig
@@ -15,7 +15,6 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-const std = @import("std");
 
 const parser = @import("../netsurf.zig");
 
diff --git a/src/browser/dom/document.zig b/src/browser/dom/document.zig
index 7d9c4ec0..22e1c0a4 100644
--- a/src/browser/dom/document.zig
+++ b/src/browser/dom/document.zig
@@ -31,8 +31,6 @@ const css = @import("css.zig");
 const Element = @import("element.zig").Element;
 const ElementUnion = @import("element.zig").Union;
 
-const DocumentType = @import("document_type.zig").DocumentType;
-const DocumentFragment = @import("document_fragment.zig").DocumentFragment;
 const DOMImplementation = @import("implementation.zig").DOMImplementation;
 
 // WEB IDL https://dom.spec.whatwg.org/#document
diff --git a/src/browser/dom/element.zig b/src/browser/dom/element.zig
index 8984d251..bf1fdfd1 100644
--- a/src/browser/dom/element.zig
+++ b/src/browser/dom/element.zig
@@ -31,8 +31,6 @@ const NodeList = @import("nodelist.zig").NodeList;
 const HTMLElem = @import("../html/elements.zig");
 pub const Union = @import("../html/elements.zig").Union;
 
-const DOMException = @import("exceptions.zig").DOMException;
-
 // WEB IDL https://dom.spec.whatwg.org/#element
 pub const Element = struct {
     pub const Self = parser.Element;
diff --git a/src/browser/dom/event_target.zig b/src/browser/dom/event_target.zig
index ffee9993..d768937a 100644
--- a/src/browser/dom/event_target.zig
+++ b/src/browser/dom/event_target.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const Env = @import("../env.zig").Env;
 const parser = @import("../netsurf.zig");
 const SessionState = @import("../env.zig").SessionState;
diff --git a/src/browser/dom/html_collection.zig b/src/browser/dom/html_collection.zig
index 9580b8f0..5ba0cb09 100644
--- a/src/browser/dom/html_collection.zig
+++ b/src/browser/dom/html_collection.zig
@@ -21,16 +21,10 @@ const Allocator = std.mem.Allocator;
 
 const parser = @import("../netsurf.zig");
 
-const utils = @import("utils.z");
 const Element = @import("element.zig").Element;
 const Union = @import("element.zig").Union;
-
 const JsThis = @import("../env.zig").JsThis;
-
 const Walker = @import("walker.zig").Walker;
-const WalkerDepthFirst = @import("walker.zig").WalkerDepthFirst;
-const WalkerChildren = @import("walker.zig").WalkerChildren;
-const WalkerNone = @import("walker.zig").WalkerNone;
 
 const Matcher = union(enum) {
     matchByName: MatchByName,
diff --git a/src/browser/dom/implementation.zig b/src/browser/dom/implementation.zig
index 03874b82..b9cbb592 100644
--- a/src/browser/dom/implementation.zig
+++ b/src/browser/dom/implementation.zig
@@ -16,13 +16,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
-const SessionState = @import("../env.zig").SessionState;
-
-const Document = @import("document.zig").Document;
-const DocumentType = @import("document_type.zig").DocumentType;
 const DOMException = @import("exceptions.zig").DOMException;
 
 // WEB IDL https://dom.spec.whatwg.org/#domimplementation
diff --git a/src/browser/dom/nodelist.zig b/src/browser/dom/nodelist.zig
index edb0d1f0..439e1eca 100644
--- a/src/browser/dom/nodelist.zig
+++ b/src/browser/dom/nodelist.zig
@@ -22,7 +22,6 @@ const parser = @import("../netsurf.zig");
 
 const JsThis = @import("../env.zig").JsThis;
 const Callback = @import("../env.zig").Callback;
-const SessionState = @import("../env.zig").SessionState;
 
 const NodeUnion = @import("node.zig").Union;
 const Node = @import("node.zig").Node;
diff --git a/src/browser/dom/text.zig b/src/browser/dom/text.zig
index 0ffbf9d9..eeccf5d8 100644
--- a/src/browser/dom/text.zig
+++ b/src/browser/dom/text.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 const SessionState = @import("../env.zig").SessionState;
 
diff --git a/src/browser/dom/token_list.zig b/src/browser/dom/token_list.zig
index 538c4156..c8b900db 100644
--- a/src/browser/dom/token_list.zig
+++ b/src/browser/dom/token_list.zig
@@ -23,7 +23,6 @@ const iterator = @import("../iterator/iterator.zig");
 
 const Callback = @import("../env.zig").Callback;
 const JsObject = @import("../env.zig").JsObject;
-const SessionState = @import("../env.zig").SessionState;
 const DOMException = @import("exceptions.zig").DOMException;
 
 const log = std.log.scoped(.token_list);
diff --git a/src/browser/dom/walker.zig b/src/browser/dom/walker.zig
index ad7ba5f7..20e889bc 100644
--- a/src/browser/dom/walker.zig
+++ b/src/browser/dom/walker.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 
 pub const Walker = union(enum) {
diff --git a/src/browser/dump.zig b/src/browser/dump.zig
index 4c4e7996..6574b1fb 100644
--- a/src/browser/dump.zig
+++ b/src/browser/dump.zig
@@ -17,7 +17,6 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const File = std.fs.File;
 
 const parser = @import("netsurf.zig");
 const Walker = @import("dom/walker.zig").WalkerChildren;
diff --git a/src/browser/events/custom_event.zig b/src/browser/events/custom_event.zig
index 53d7e1b2..a855beac 100644
--- a/src/browser/events/custom_event.zig
+++ b/src/browser/events/custom_event.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 const Event = @import("event.zig").Event;
 const JsObject = @import("../env.zig").JsObject;
diff --git a/src/browser/html/document.zig b/src/browser/html/document.zig
index b7437c5e..95619940 100644
--- a/src/browser/html/document.zig
+++ b/src/browser/html/document.zig
@@ -21,10 +21,8 @@ const std = @import("std");
 const parser = @import("../netsurf.zig");
 const SessionState = @import("../env.zig").SessionState;
 
-const Node = @import("../dom/node.zig").Node;
 const Document = @import("../dom/document.zig").Document;
 const NodeList = @import("../dom/nodelist.zig").NodeList;
-const HTMLElem = @import("elements.zig");
 const Location = @import("location.zig").Location;
 
 const collection = @import("../dom/html_collection.zig");
diff --git a/src/browser/html/history.zig b/src/browser/html/history.zig
index 0bd07f9c..592d26fd 100644
--- a/src/browser/html/history.zig
+++ b/src/browser/html/history.zig
@@ -18,8 +18,6 @@
 
 const std = @import("std");
 
-const builtin = @import("builtin");
-
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-history-interface
 pub const History = struct {
     const ScrollRestorationMode = enum {
diff --git a/src/browser/html/location.zig b/src/browser/html/location.zig
index 08f6aa4c..52968d13 100644
--- a/src/browser/html/location.zig
+++ b/src/browser/html/location.zig
@@ -16,12 +16,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const SessionState = @import("../env.zig").SessionState;
 
-const builtin = @import("builtin");
-
 const URL = @import("../url/url.zig").URL;
 
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-location-interface
diff --git a/src/browser/iterator/iterator.zig b/src/browser/iterator/iterator.zig
index cb7a1c04..c0b8aa07 100644
--- a/src/browser/iterator/iterator.zig
+++ b/src/browser/iterator/iterator.zig
@@ -1,5 +1,3 @@
-const std = @import("std");
-
 pub const Interfaces = .{
     U32Iterator,
 };
diff --git a/src/browser/mimalloc.zig b/src/browser/mimalloc.zig
index 0206edc9..0cb15156 100644
--- a/src/browser/mimalloc.zig
+++ b/src/browser/mimalloc.zig
@@ -21,7 +21,6 @@
 // We replace the libdom default usage of allocations with mimalloc heap
 // allocation to be able to free all memory used at once, like an arena usage.
 
-const std = @import("std");
 const c = @cImport({
     @cInclude("mimalloc.h");
 });
diff --git a/src/browser/polyfill/fetch.zig b/src/browser/polyfill/fetch.zig
index 7866628a..a0166bdd 100644
--- a/src/browser/polyfill/fetch.zig
+++ b/src/browser/polyfill/fetch.zig
@@ -1,4 +1,3 @@
-const std = @import("std");
 // fetch.js code comes from
 // https://github.com/JakeChampion/fetch/blob/main/fetch.js
 //
diff --git a/src/browser/xhr/progress_event.zig b/src/browser/xhr/progress_event.zig
index 4fd8b8a7..5cdd8dd5 100644
--- a/src/browser/xhr/progress_event.zig
+++ b/src/browser/xhr/progress_event.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 const parser = @import("../netsurf.zig");
 const Event = @import("../events/event.zig").Event;
 
diff --git a/src/browser/xmlserializer/xmlserializer.zig b/src/browser/xmlserializer/xmlserializer.zig
index ea2a4697..207db972 100644
--- a/src/browser/xmlserializer/xmlserializer.zig
+++ b/src/browser/xmlserializer/xmlserializer.zig
@@ -22,7 +22,6 @@ const SessionState = @import("../env.zig").SessionState;
 
 const dump = @import("../dump.zig");
 const parser = @import("../netsurf.zig");
-const DOMError = parser.DOMError;
 
 pub const Interfaces = .{
     XMLSerializer,
diff --git a/src/cdp/domains/emulation.zig b/src/cdp/domains/emulation.zig
index 84e1b56b..dd94df3e 100644
--- a/src/cdp/domains/emulation.zig
+++ b/src/cdp/domains/emulation.zig
@@ -17,7 +17,6 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const Runtime = @import("runtime.zig");
 
 pub fn processMessage(cmd: anytype) !void {
     const action = std.meta.stringToEnum(enum {
diff --git a/src/cdp/domains/page.zig b/src/cdp/domains/page.zig
index 676db373..0ad74f09 100644
--- a/src/cdp/domains/page.zig
+++ b/src/cdp/domains/page.zig
@@ -17,7 +17,6 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 const std = @import("std");
-const runtime = @import("runtime.zig");
 const URL = @import("../../url.zig").URL;
 const Notification = @import("../../notification.zig").Notification;
 
diff --git a/src/cdp/testing.zig b/src/cdp/testing.zig
index 045fa7ee..8897fad8 100644
--- a/src/cdp/testing.zig
+++ b/src/cdp/testing.zig
@@ -24,7 +24,6 @@ const ArenaAllocator = std.heap.ArenaAllocator;
 const Testing = @This();
 
 const main = @import("cdp.zig");
-const URL = @import("../url.zig").URL;
 const App = @import("../app.zig").App;
 const parser = @import("../browser/netsurf.zig");
 
diff --git a/src/id.zig b/src/id.zig
index 7dd86627..d2944cdf 100644
--- a/src/id.zig
+++ b/src/id.zig
@@ -88,16 +88,6 @@ pub fn uuidv4(hex: []u8) void {
     }
 }
 
-const hex_to_nibble = [_]u8{0xff} ** 48 ++ [_]u8{
-    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-    0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-    0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0xff,
-    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-    0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0xff,
-} ++ [_]u8{0xff} ** 152;
-
 const testing = std.testing;
 test "id: Incrementing.next" {
     var id = Incrementing(u16, "IDX"){};
diff --git a/src/runtime/test_primitive_types.zig b/src/runtime/test_primitive_types.zig
index eccf5202..5c003481 100644
--- a/src/runtime/test_primitive_types.zig
+++ b/src/runtime/test_primitive_types.zig
@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-const std = @import("std");
-
 // TODO: use functions instead of "fake" struct once we handle function API generation
 const Primitives = struct {
     pub fn constructor() Primitives {
diff --git a/src/server.zig b/src/server.zig
index 471c2cf2..0a65c5b0 100644
--- a/src/server.zig
+++ b/src/server.zig
@@ -30,8 +30,6 @@ const Completion = IO.Completion;
 const AcceptError = IO.AcceptError;
 const RecvError = IO.RecvError;
 const SendError = IO.SendError;
-const CloseError = IO.CloseError;
-const CancelError = IO.CancelOneError;
 const TimeoutError = IO.TimeoutError;
 const Loop = @import("runtime/loop.zig").Loop;
 
@@ -947,10 +945,6 @@ const OpCode = enum(u8) {
     pong = 128 | 10,
 };
 
-const CloseCode = enum {
-    timeout,
-};
-
 fn fillWebsocketHeader(buf: std.ArrayListUnmanaged(u8)) []const u8 {
     // can't use buf[0..10] here, because the header length
     // is variable. If it's just 2 bytes, for example, we need the
diff --git a/src/telemetry/lightpanda.zig b/src/telemetry/lightpanda.zig
index b1cabd51..06b0a610 100644
--- a/src/telemetry/lightpanda.zig
+++ b/src/telemetry/lightpanda.zig
@@ -26,7 +26,7 @@ pub const LightPanda = struct {
 
     const List = std.DoublyLinkedList(LightPandaEvent);
 
-    pub fn init(app: *App) !LightPanda {
+    pub fn init(app: *App) LightPanda {
         const allocator = app.allocator;
         return .{
             .cond = .{},
diff --git a/src/telemetry/telemetry.zig b/src/telemetry/telemetry.zig
index b254654a..0a46b6cb 100644
--- a/src/telemetry/telemetry.zig
+++ b/src/telemetry/telemetry.zig
@@ -4,7 +4,6 @@ const builtin = @import("builtin");
 const Allocator = std.mem.Allocator;
 
 const App = @import("../app.zig").App;
-const Loop = @import("jsruntime").Loop;
 const Notification = @import("../notification.zig").Notification;
 
 const uuidv4 = @import("../id.zig").uuidv4;
@@ -39,7 +38,7 @@ fn TelemetryT(comptime P: type) type {
             return .{
                 .disabled = disabled,
                 .run_mode = run_mode,
-                .provider = try P.init(app),
+                .provider = P.init(app),
                 .iid = if (disabled) null else getOrCreateId(app.app_dir_path),
             };
         }
@@ -135,7 +134,7 @@ pub const Event = union(enum) {
 };
 
 const NoopProvider = struct {
-    fn init(_: *App) !NoopProvider {
+    fn init(_: *App) NoopProvider {
         return .{};
     }
     fn deinit(_: NoopProvider) void {}
@@ -151,7 +150,7 @@ test "telemetry: disabled by environment" {
     defer _ = unsetenv(@constCast("LIGHTPANDA_DISABLE_TELEMETRY"));
 
     const FailingProvider = struct {
-        fn init(_: *App) !@This() {
+        fn init(_: *App) @This() {
             return .{};
         }
         fn deinit(_: @This()) void {}
@@ -207,7 +206,7 @@ const MockProvider = struct {
     allocator: Allocator,
     events: std.ArrayListUnmanaged(Event),
 
-    fn init(app: *App) !@This() {
+    fn init(app: *App) @This() {
         return .{
             .iid = null,
             .run_mode = null,