diff --git a/web/src/billing/helpers.ts b/web/src/billing/helpers.ts
index 00473c1d8e..f4c641c3e3 100644
--- a/web/src/billing/helpers.ts
+++ b/web/src/billing/helpers.ts
@@ -80,7 +80,7 @@ export function create_ajax_request(
         },
         error(xhr) {
             $(form_loading).hide();
-            $(form_error).show().text(JSON.parse(xhr.responseText).msg);
+            $(form_error).show().text(xhr.responseJSON.msg);
             $(form_input_section).show();
             $(zulip_limited_section).show();
             $(free_trial_alert_message).show();
diff --git a/web/src/channel.js b/web/src/channel.js
index d294f1c7c3..2024ed8e99 100644
--- a/web/src/channel.js
+++ b/web/src/channel.js
@@ -107,7 +107,7 @@ function call(args) {
         } else if (xhr.status === 403) {
             try {
                 if (
-                    JSON.parse(xhr.responseText).code === "CSRF_FAILED" &&
+                    xhr.responseJSON.code === "CSRF_FAILED" &&
                     reload_state.csrf_failed_handler !== undefined
                 ) {
                     reload_state.csrf_failed_handler();
@@ -192,7 +192,7 @@ export function xhr_error_message(message, xhr) {
     if (xhr.status.toString().charAt(0) === "4") {
         // Only display the error response for 4XX, where we've crafted
         // a nice response.
-        const server_response_html = _.escape(JSON.parse(xhr.responseText).msg);
+        const server_response_html = _.escape(xhr.responseJSON.msg);
         if (message) {
             message += ": " + server_response_html;
         } else {
diff --git a/web/src/compose.js b/web/src/compose.js
index d57bd6e0fe..a203df2472 100644
--- a/web/src/compose.js
+++ b/web/src/compose.js
@@ -595,7 +595,7 @@ export function initialize() {
             }
 
             function xhr_failure(xhr) {
-                const error = JSON.parse(xhr.responseText);
+                const error = xhr.responseJSON;
                 failure(error.msg);
             }
 
diff --git a/web/src/invite.js b/web/src/invite.js
index 4def7e906d..9c5048f041 100644
--- a/web/src/invite.js
+++ b/web/src/invite.js
@@ -114,16 +114,16 @@ function submit_invitation_form() {
             }
         },
         error(xhr) {
-            const arr = JSON.parse(xhr.responseText);
-            if (arr.errors === undefined) {
+            if (xhr.responseJSON.errors === undefined) {
                 // There was a fatal error, no partial processing occurred.
                 ui_report.error("", xhr, $invite_status);
             } else {
                 // Some users were not invited.
+                const response_body = xhr.responseJSON;
                 const invitee_emails_errored = [];
                 const error_list = [];
                 let is_invitee_deactivated = false;
-                for (const value of arr.errors) {
+                for (const value of response_body.errors) {
                     const [email, error_message, deactivated] = value;
                     error_list.push(`${email}: ${error_message}`);
                     if (deactivated) {
@@ -133,17 +133,17 @@ function submit_invitation_form() {
                 }
 
                 const error_response = render_invitation_failed_error({
-                    error_message: arr.msg,
+                    error_message: response_body.msg,
                     error_list,
                     is_admin: page_params.is_admin,
                     is_invitee_deactivated,
-                    license_limit_reached: arr.license_limit_reached,
+                    license_limit_reached: response_body.license_limit_reached,
                     has_billing_access: page_params.is_owner || page_params.is_billing_admin,
-                    daily_limit_reached: arr.daily_limit_reached,
+                    daily_limit_reached: response_body.daily_limit_reached,
                 });
                 ui_report.message(error_response, $invite_status, "alert-warning");
 
-                if (arr.sent_invitations) {
+                if (response_body.sent_invitations) {
                     $invitee_emails.val(invitee_emails_errored.join("\n"));
                 }
             }
diff --git a/web/src/message_edit.js b/web/src/message_edit.js
index 27926a38b2..f74c3b62ec 100644
--- a/web/src/message_edit.js
+++ b/web/src/message_edit.js
@@ -699,8 +699,7 @@ export function toggle_resolve_topic(message_id, old_topic_name, report_errors_i
             }
 
             if (report_errors_in_global_banner) {
-                const error_msg = JSON.parse(xhr.responseText).msg;
-                ui_report.generic_embed_error(error_msg, 3500);
+                ui_report.generic_embed_error(xhr.responseJSON.msg, 3500);
             }
         },
     });
diff --git a/web/src/server_events.js b/web/src/server_events.js
index 5cf410c577..a9b8a29875 100644
--- a/web/src/server_events.js
+++ b/web/src/server_events.js
@@ -207,10 +207,7 @@ function get_events({dont_block = false} = {}) {
                 get_events_xhr = undefined;
                 // If we're old enough that our message queue has been
                 // garbage collected, immediately reload.
-                if (
-                    xhr.status === 400 &&
-                    JSON.parse(xhr.responseText).code === "BAD_EVENT_QUEUE_ID"
-                ) {
+                if (xhr.status === 400 && xhr.responseJSON.code === "BAD_EVENT_QUEUE_ID") {
                     page_params.event_queue_expired = true;
                     reload.initiate({
                         immediate: true,
diff --git a/web/src/settings_account.js b/web/src/settings_account.js
index b7eb4a6f04..c36ae4c389 100644
--- a/web/src/settings_account.js
+++ b/web/src/settings_account.js
@@ -119,7 +119,7 @@ function upload_avatar($file_input) {
                 $("#user-avatar-source").show();
             }
             const $error = $("#user-avatar-upload-widget .image_file_input_error");
-            $error.text(JSON.parse(xhr.responseText).msg);
+            $error.text(xhr.responseJSON.msg);
             $error.show();
         },
     });
@@ -490,7 +490,7 @@ export function set_up() {
                     $("#api_key_value").text(data.api_key);
                 },
                 error(xhr) {
-                    $("#user_api_key_error").text(JSON.parse(xhr.responseText).msg).show();
+                    $("#user_api_key_error").text(xhr.responseJSON.msg).show();
                 },
             });
             e.preventDefault();
diff --git a/web/src/settings_bots.js b/web/src/settings_bots.js
index c45ddb6323..b6286e0745 100644
--- a/web/src/settings_bots.js
+++ b/web/src/settings_bots.js
@@ -581,7 +581,7 @@ export function set_up() {
             },
             error(xhr) {
                 const $row = $(e.currentTarget).closest("li");
-                $row.find(".api_key_error").text(JSON.parse(xhr.responseText).msg).show();
+                $row.find(".api_key_error").text(xhr.responseJSON.msg).show();
             },
         });
     });
diff --git a/web/src/settings_linkifiers.js b/web/src/settings_linkifiers.js
index dc87b76788..1c58a388ee 100644
--- a/web/src/settings_linkifiers.js
+++ b/web/src/settings_linkifiers.js
@@ -73,7 +73,7 @@ function open_linkifier_edit_form(linkifier_id) {
             },
             error_continuation(xhr) {
                 $change_linkifier_button.prop("disabled", false);
-                const response_text = JSON.parse(xhr.responseText);
+                const response_text = xhr.responseJSON;
                 if (response_text.errors !== undefined) {
                     handle_linkifier_api_error(
                         xhr,
@@ -113,17 +113,17 @@ function handle_linkifier_api_error(xhr, pattern_status, template_status, linkif
     // The endpoint uses the Django ValidationError system for error
     // handling, which returns somewhat complicated error
     // dictionaries. This logic parses them.
-    const errors = JSON.parse(xhr.responseText).errors;
+    const errors = xhr.responseJSON.errors;
     if (errors.pattern !== undefined) {
-        xhr.responseText = JSON.stringify({msg: errors.pattern});
+        xhr.responseJSON.msg = errors.pattern;
         ui_report.error($t_html({defaultMessage: "Failed"}), xhr, pattern_status);
     }
     if (errors.url_template !== undefined) {
-        xhr.responseText = JSON.stringify({msg: errors.url_template});
+        xhr.responseJSON.msg = errors.url_template;
         ui_report.error($t_html({defaultMessage: "Failed"}), xhr, template_status);
     }
     if (errors.__all__ !== undefined) {
-        xhr.responseText = JSON.stringify({msg: errors.__all__});
+        xhr.responseJSON.msg = errors.__all__;
         ui_report.error($t_html({defaultMessage: "Failed"}), xhr, linkifier_status);
     }
 }
diff --git a/web/src/stats/stats.js b/web/src/stats/stats.js
index c31cd438c9..579d453541 100644
--- a/web/src/stats/stats.js
+++ b/web/src/stats/stats.js
@@ -1101,7 +1101,7 @@ function get_chart_data(data, callback) {
             update_last_full_update(data.end_times);
         },
         error(xhr) {
-            $("#id_stats_errors").show().text(JSON.parse(xhr.responseText).msg);
+            $("#id_stats_errors").show().text(xhr.responseJSON.msg);
         },
     });
 }
diff --git a/web/src/stream_create.js b/web/src/stream_create.js
index 7bd822f8e6..5d9e636ce2 100644
--- a/web/src/stream_create.js
+++ b/web/src/stream_create.js
@@ -280,7 +280,7 @@ function create_stream() {
             // The rest of the work is done via the subscribe event we will get
         },
         error(xhr) {
-            const msg = JSON.parse(xhr.responseText).msg;
+            const msg = xhr.responseJSON.msg;
             if (msg.includes("access")) {
                 // If we can't access the stream, we can safely
                 // assume it's a duplicate stream that we are not invited to.
diff --git a/web/src/stream_edit_subscribers.js b/web/src/stream_edit_subscribers.js
index b97cfac696..0b4d448588 100644
--- a/web/src/stream_edit_subscribers.js
+++ b/web/src/stream_edit_subscribers.js
@@ -196,7 +196,7 @@ function subscribe_new_users({pill_user_ids}) {
     }
 
     function invite_failure(xhr) {
-        const error = JSON.parse(xhr.responseText);
+        const error = xhr.responseJSON;
         show_stream_subscription_request_result({
             message: error.msg,
             add_class: "text-error",
diff --git a/web/src/stream_settings_ui.js b/web/src/stream_settings_ui.js
index bcbc3bad1c..a4cebb09b7 100644
--- a/web/src/stream_settings_ui.js
+++ b/web/src/stream_settings_ui.js
@@ -957,7 +957,7 @@ function ajaxSubscribe(stream, color, $stream_row) {
                 $("#create_stream_name").val("");
             }
 
-            const res = JSON.parse(xhr.responseText);
+            const res = xhr.responseJSON;
             if (!$.isEmptyObject(res.already_subscribed)) {
                 // Display the canonical stream capitalization.
                 true_stream_name = res.already_subscribed[people.my_current_email()][0];
diff --git a/web/src/ui_report.ts b/web/src/ui_report.ts
index 5763bdc3db..da21819833 100644
--- a/web/src/ui_report.ts
+++ b/web/src/ui_report.ts
@@ -41,7 +41,7 @@ export function error(
     if (xhr && xhr.status >= 400 && xhr.status < 500) {
         // Only display the error response for 4XX, where we've crafted
         // a nice response.
-        const server_response_html = _.escape(JSON.parse(xhr.responseText).msg);
+        const server_response_html = _.escape(xhr.responseJSON.msg);
         if (response_html) {
             response_html += ": " + server_response_html;
         } else {
@@ -79,7 +79,7 @@ export function generic_embed_error(error_html: string, remove_after: number): v
 
 export function generic_row_button_error(xhr: JQuery.jqXHR, $btn: JQuery): void {
     if (xhr.status >= 400 && xhr.status < 500) {
-        const $error = $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg);
+        const $error = $("<p>").addClass("text-error").text(xhr.responseJSON.msg);
         $btn.closest("td").empty().append($error);
     } else {
         $btn.text($t({defaultMessage: "Failed!"}));
diff --git a/web/src/user_group_edit_members.js b/web/src/user_group_edit_members.js
index 5bb674f1de..5b836f960a 100644
--- a/web/src/user_group_edit_members.js
+++ b/web/src/user_group_edit_members.js
@@ -223,7 +223,7 @@ function add_new_members({pill_user_ids}) {
     }
 
     function invite_failure(xhr) {
-        const error = JSON.parse(xhr.responseText);
+        const error = xhr.responseJSON;
         show_user_group_membership_request_result({
             message: error.msg,
             add_class: "text-error",
diff --git a/web/tests/billing_helpers.test.js b/web/tests/billing_helpers.test.js
index 6cfbee3240..648426ef00 100644
--- a/web/tests/billing_helpers.test.js
+++ b/web/tests/billing_helpers.test.js
@@ -160,7 +160,7 @@ run_test("create_ajax_request", ({override}) => {
         assert.equal(state.free_trial_alert_message_show, 0);
         assert.ok(success_callback_called);
 
-        error({responseText: '{"msg": "response_message"}'});
+        error({responseJSON: {msg: "response_message"}});
 
         assert.equal(state.form_loading_hide, 2);
         assert.equal(state.form_error_show, 1);
diff --git a/web/tests/channel.test.js b/web/tests/channel.test.js
index b0ac3712e8..c2dd86517f 100644
--- a/web/tests/channel.test.js
+++ b/web/tests/channel.test.js
@@ -9,7 +9,7 @@ const {page_params} = require("./lib/zpage_params");
 
 const xhr_401 = {
     status: 401,
-    responseText: '{"msg": "Use cannot access XYZ"}',
+    responseJSON: {msg: "Use cannot access XYZ"},
 };
 
 let login_to_access_shown = false;
@@ -294,7 +294,7 @@ test("reload_on_403_error", () => {
     test_with_mock_ajax({
         xhr: {
             status: 403,
-            responseText: '{"msg": "CSRF Fehler: etwas", "code": "CSRF_FAILED"}',
+            responseJSON: {msg: "CSRF Fehler: etwas", code: "CSRF_FAILED"},
         },
 
         run_code() {
@@ -317,6 +317,7 @@ test("unexpected_403_response", () => {
     test_with_mock_ajax({
         xhr: {
             status: 403,
+            responseJSON: undefined,
             responseText: "unexpected",
         },
 
@@ -334,6 +335,7 @@ test("unexpected_403_response", () => {
 test("xhr_error_message", () => {
     let xhr = {
         status: "200",
+        responseJSON: undefined,
         responseText: "does not matter",
     };
     let msg = "data added";
@@ -341,7 +343,7 @@ test("xhr_error_message", () => {
 
     xhr = {
         status: "404",
-        responseText: '{"msg": "file not found"}',
+        responseJSON: {msg: "file not found"},
     };
     msg = "some message";
     assert.equal(channel.xhr_error_message(msg, xhr), "some message: file not found");