diff --git a/src/browser/fetch/Headers.zig b/src/browser/fetch/Headers.zig
index 74157263..e6acd935 100644
--- a/src/browser/fetch/Headers.zig
+++ b/src/browser/fetch/Headers.zig
@@ -79,8 +79,8 @@ pub fn constructor(_init: ?HeadersInit, page: *Page) !Headers {
                         return error.TypeError;
                     }
 
-                    const key = try page.arena.dupe(u8, pair[0]);
-                    const value = try page.arena.dupe(u8, pair[1]);
+                    const key = try arena.dupe(u8, pair[0]);
+                    const value = try arena.dupe(u8, pair[1]);
 
                     try headers.put(arena, key, value);
                 }
@@ -88,8 +88,8 @@ pub fn constructor(_init: ?HeadersInit, page: *Page) !Headers {
             .headers => |hdrs| {
                 var iter = hdrs.headers.iterator();
                 while (iter.next()) |entry| {
-                    const key = try page.arena.dupe(u8, entry.key_ptr.*);
-                    const value = try page.arena.dupe(u8, entry.value_ptr.*);
+                    const key = try arena.dupe(u8, entry.key_ptr.*);
+                    const value = try arena.dupe(u8, entry.value_ptr.*);
                     try headers.put(arena, key, value);
                 }
             },
@@ -129,10 +129,29 @@ pub fn _delete(self: *Headers, name: []const u8) void {
     _ = self.headers.remove(name);
 }
 
-// TODO: entries iterator
-// They should be:
-// 1. Sorted in lexicographical order.
-// 2. Duplicate header names should be combined.
+pub const HeaderEntryIterator = struct {
+    slot: [][]const u8,
+    iter: *HeaderHashMap.Iterator,
+
+    // TODO: these SHOULD be in lexigraphical order but I'm not sure how actually
+    // important that is.
+    pub fn _next(self: *HeaderEntryIterator) !?[]const []const u8 {
+        if (self.iter.next()) |entry| {
+            self.slot[0] = entry.key_ptr.*;
+            self.slot[1] = entry.value_ptr.*;
+            return self.slot;
+        } else {
+            return null;
+        }
+    }
+};
+
+pub fn _entries(self: *const Headers, page: *Page) !HeaderEntryIterator {
+    const iter = try page.arena.create(HeaderHashMap.Iterator);
+    iter.* = self.headers.iterator();
+
+    return .{ .slot = try page.arena.alloc([]const u8, 2), .iter = iter };
+}
 
 pub fn _forEach(self: *Headers, callback_fn: Env.Function, this_arg: ?Env.JsObject) !void {
     var iter = self.headers.iterator();
@@ -163,7 +182,24 @@ pub fn _has(self: *const Headers, name: []const u8) bool {
     return self.headers.contains(name);
 }
 
-// TODO: keys iterator
+pub const HeaderKeyIterator = struct {
+    iter: *HeaderHashMap.KeyIterator,
+
+    pub fn _next(self: *HeaderKeyIterator) !?[]const u8 {
+        if (self.iter.next()) |key| {
+            return key.*;
+        } else {
+            return null;
+        }
+    }
+};
+
+pub fn _keys(self: *const Headers, page: *Page) !HeaderKeyIterator {
+    const iter = try page.arena.create(HeaderHashMap.KeyIterator);
+    iter.* = self.headers.keyIterator();
+
+    return .{ .iter = iter };
+}
 
 pub fn _set(self: *Headers, name: []const u8, value: []const u8, page: *Page) !void {
     const arena = page.arena;
@@ -172,7 +208,23 @@ pub fn _set(self: *Headers, name: []const u8, value: []const u8, page: *Page) !v
     gop.value_ptr.* = try arena.dupe(u8, value);
 }
 
-// TODO: values iterator
+pub const HeaderValueIterator = struct {
+    iter: *HeaderHashMap.ValueIterator,
+
+    pub fn _next(self: *HeaderValueIterator) !?[]const u8 {
+        if (self.iter.next()) |value| {
+            return value.*;
+        } else {
+            return null;
+        }
+    }
+};
+
+pub fn _values(self: *const Headers, page: *Page) !HeaderValueIterator {
+    const iter = try page.arena.create(HeaderHashMap.ValueIterator);
+    iter.* = self.headers.valueIterator();
+    return .{ .iter = iter };
+}
 
 const testing = @import("../../testing.zig");
 test "fetch: headers" {
diff --git a/src/browser/fetch/Request.zig b/src/browser/fetch/Request.zig
index 6f4e3751..cf59c32e 100644
--- a/src/browser/fetch/Request.zig
+++ b/src/browser/fetch/Request.zig
@@ -98,7 +98,7 @@ pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Re
     const arena = page.arena;
     const options: RequestInit = _options orelse .{};
 
-    const url = blk: switch (input) {
+    const url: [:0]const u8 = blk: switch (input) {
         .string => |str| {
             break :blk try URL.stitch(arena, str, page.url.raw, .{ .null_terminated = true });
         },
@@ -111,7 +111,7 @@ pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Re
     const cache = (if (options.cache) |cache| RequestCache.fromString(cache) else null) orelse RequestCache.default;
     const credentials = (if (options.credentials) |creds| RequestCredentials.fromString(creds) else null) orelse RequestCredentials.@"same-origin";
     const integrity = if (options.integrity) |integ| try arena.dupe(u8, integ) else "";
-    const headers = if (options.headers) |hdrs| try Headers.constructor(hdrs, page) else Headers{};
+    const headers: Headers = if (options.headers) |hdrs| try Headers.constructor(hdrs, page) else .{};
 
     const method: Http.Method = blk: {
         if (options.method) |given_method| {
diff --git a/src/browser/fetch/Response.zig b/src/browser/fetch/Response.zig
index 21a950de..858e8487 100644
--- a/src/browser/fetch/Response.zig
+++ b/src/browser/fetch/Response.zig
@@ -37,7 +37,7 @@ const Page = @import("../page.zig").Page;
 const Response = @This();
 
 status: u16 = 0,
-headers: Headers = .{},
+headers: Headers,
 mime: ?Mime = null,
 url: []const u8 = "",
 body: []const u8 = "",
diff --git a/src/browser/fetch/fetch.zig b/src/browser/fetch/fetch.zig
index fc8e9b78..a9e47ea8 100644
--- a/src/browser/fetch/fetch.zig
+++ b/src/browser/fetch/fetch.zig
@@ -26,6 +26,7 @@ const Page = @import("../page.zig").Page;
 const Http = @import("../../http/Http.zig");
 const HttpClient = @import("../../http/Client.zig");
 const Mime = @import("../mime.zig").Mime;
+
 const Headers = @import("Headers.zig");
 
 const RequestInput = @import("Request.zig").RequestInput;
@@ -35,6 +36,9 @@ const Response = @import("Response.zig");
 
 pub const Interfaces = .{
     @import("Headers.zig"),
+    @import("Headers.zig").HeaderEntryIterator,
+    @import("Headers.zig").HeaderKeyIterator,
+    @import("Headers.zig").HeaderValueIterator,
     @import("Request.zig"),
     @import("Response.zig"),
 };
@@ -157,6 +161,7 @@ pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !Env.Promi
         .done_callback = struct {
             fn doneCallback(ctx: *anyopaque) !void {
                 const self: *FetchContext = @ptrCast(@alignCast(ctx));
+                self.transfer = null;
 
                 log.info(.http, "request complete", .{
                     .source = "fetch",
@@ -177,8 +182,8 @@ pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !Env.Promi
         .error_callback = struct {
             fn errorCallback(ctx: *anyopaque, err: anyerror) void {
                 const self: *FetchContext = @ptrCast(@alignCast(ctx));
-
                 self.transfer = null;
+
                 const promise_resolver: Env.PromiseResolver = .{
                     .js_context = self.js_ctx,
                     .resolver = self.promise_resolver.castToPromiseResolver(),