diff --git a/cmd/gotosocial/action/testrig/testrig.go b/cmd/gotosocial/action/testrig/testrig.go
index f6721d8b6..0036b7a7d 100644
--- a/cmd/gotosocial/action/testrig/testrig.go
+++ b/cmd/gotosocial/action/testrig/testrig.go
@@ -20,11 +20,9 @@
 package testrig
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
-	"io"
 	"net/http"
 	"os"
 	"os/signal"
@@ -160,16 +158,8 @@
 	testrig.StandardStorageSetup(state.Storage, "./testrig/media")
 
 	// build backend handlers
-	transportController := testrig.NewTestTransportController(state, testrig.NewMockHTTPClient(func(req *http.Request) (*http.Response, error) {
-		r := io.NopCloser(bytes.NewReader([]byte{}))
-		return &http.Response{
-			StatusCode: 200,
-			Body:       r,
-			Header: http.Header{
-				"Content-Type": req.Header.Values("Accept"),
-			},
-		}, nil
-	}, ""))
+	httpClient := testrig.NewMockHTTPClient(nil, "./testrig/media")
+	transportController := testrig.NewTestTransportController(state, httpClient)
 	mediaManager := testrig.NewTestMediaManager(state)
 	federator := testrig.NewTestFederator(state, transportController, mediaManager)
 
diff --git a/web/source/settings/components/pageable-list.tsx b/web/source/settings/components/pageable-list.tsx
index 3571fb1cd..92c5e220d 100644
--- a/web/source/settings/components/pageable-list.tsx
+++ b/web/source/settings/components/pageable-list.tsx
@@ -30,7 +30,7 @@ export interface PageableListProps<T> {
 	items?: T[];
 	itemToEntry: (_item: T) => ReactNode;
 	isLoading: boolean;
-	isFetching: boolean;
+	isFetching?: boolean;
 	isError: boolean;
 	error: FetchBaseQueryError | SerializedError | undefined;
 	emptyMessage: ReactNode;
diff --git a/web/source/settings/lib/query/admin/domain-permissions/subscriptions.ts b/web/source/settings/lib/query/admin/domain-permissions/subscriptions.ts
index f065aaf54..fef512a56 100644
--- a/web/source/settings/lib/query/admin/domain-permissions/subscriptions.ts
+++ b/web/source/settings/lib/query/admin/domain-permissions/subscriptions.ts
@@ -20,6 +20,7 @@
 import { gtsApi } from "../../gts-api";
 
 import type {
+	DomainPerm,
 	DomainPermSub,
 	DomainPermSubCreateUpdateParams,
 	DomainPermSubSearchParams,
@@ -120,6 +121,13 @@ const extended = gtsApi.injectEndpoints({
 				asForm: true,
 				body: { remove_children: remove_children },
 			}),
+		}),
+
+		testDomainPermissionSubscription: build.mutation<{ error: string } | DomainPerm[], string>({
+			query: (id) => ({
+				method: "POST",
+				url: `/api/v1/admin/domain_permission_subscriptions/${id}/test`,
+			}),
 		})
 	}),
 });
@@ -154,6 +162,11 @@ const useUpdateDomainPermissionSubscriptionMutation = extended.useUpdateDomainPe
  */
 const useRemoveDomainPermissionSubscriptionMutation = extended.useRemoveDomainPermissionSubscriptionMutation;
 
+/**
+ * Test a domain permission subscription to see if data can be fetched + parsed.
+ */
+const useTestDomainPermissionSubscriptionMutation = extended.useTestDomainPermissionSubscriptionMutation;
+
 export {
 	useLazySearchDomainPermissionSubscriptionsQuery,
 	useGetDomainPermissionSubscriptionQuery,
@@ -161,4 +174,5 @@ export {
 	useGetDomainPermissionSubscriptionsPreviewQuery,
 	useUpdateDomainPermissionSubscriptionMutation,
 	useRemoveDomainPermissionSubscriptionMutation,
+	useTestDomainPermissionSubscriptionMutation,
 };
diff --git a/web/source/settings/style.css b/web/source/settings/style.css
index bbb8fd61c..75e7e7e3f 100644
--- a/web/source/settings/style.css
+++ b/web/source/settings/style.css
@@ -1426,6 +1426,18 @@ button.tab-button {
 	}
 }
 
+.domain-permission-subscription-details {
+	> .list > .entries > .perm-preview {
+		gap: 0.5rem;
+	}
+
+	> .perm-issue > b > code {
+		background: $info-bg;
+		padding: 0;
+	}
+}
+
+
 .domain-permission-subscription-title {
 	font-size: 1.2rem;
 	font-weight: bold;
@@ -1451,7 +1463,8 @@ button.tab-button {
 	}
 }
 
-.domain-permission-subscription-remove {
+.domain-permission-subscription-remove,
+.domain-permission-subscription-test {
 	gap: 1rem;
 }
 
diff --git a/web/source/settings/views/moderation/domain-permissions/subscriptions/detail.tsx b/web/source/settings/views/moderation/domain-permissions/subscriptions/detail.tsx
index 408d81b92..06f1582ae 100644
--- a/web/source/settings/views/moderation/domain-permissions/subscriptions/detail.tsx
+++ b/web/source/settings/views/moderation/domain-permissions/subscriptions/detail.tsx
@@ -17,19 +17,20 @@
 	along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-import React, { useState } from "react";
+import React, { ReactNode, useState } from "react";
 import { useLocation, useParams } from "wouter";
 import { useBaseUrl } from "../../../../lib/navigation/util";
 import BackButton from "../../../../components/back-button";
-import { useGetDomainPermissionSubscriptionQuery, useRemoveDomainPermissionSubscriptionMutation, useUpdateDomainPermissionSubscriptionMutation } from "../../../../lib/query/admin/domain-permissions/subscriptions";
+import { useGetDomainPermissionSubscriptionQuery, useRemoveDomainPermissionSubscriptionMutation, useTestDomainPermissionSubscriptionMutation, useUpdateDomainPermissionSubscriptionMutation } from "../../../../lib/query/admin/domain-permissions/subscriptions";
 import { useBoolInput, useNumberInput, useTextInput } from "../../../../lib/form";
 import FormWithData from "../../../../lib/form/form-with-data";
-import { DomainPermSub } from "../../../../lib/types/domain-permission";
+import { DomainPerm, DomainPermSub } from "../../../../lib/types/domain-permission";
 import MutationButton from "../../../../components/form/mutation-button";
 import { Checkbox, NumberInput, Select, TextInput } from "../../../../components/form/inputs";
 import useFormSubmit from "../../../../lib/form/submit";
 import UsernameLozenge from "../../../../components/username-lozenge";
 import { urlValidator } from "../../../../lib/util/formvalidators";
+import { PageableList } from "../../../../components/pageable-list";
 
 export default function DomainPermissionSubscriptionDetail() {
 	const params = useParams();
@@ -56,6 +57,7 @@ function DomainPermSubForm({ data: permSub }: { data: DomainPermSub }) {
 			<h1><BackButton to={backLocation} /> Domain Permission Subscription Detail</h1>
 			<DomainPermSubDetails permSub={permSub} />
 			<UpdateDomainPermSub permSub={permSub} />
+			<TestDomainPermSub permSub={permSub} />
 			<DeleteDomainPermSub permSub={permSub} backLocation={backLocation} />
 		</div>
 	);
@@ -382,3 +384,73 @@ function DeleteDomainPermSub({ permSub, backLocation }: { permSub: DomainPermSub
 		</form>
 	);
 }
+
+function TestDomainPermSub({ permSub }: { permSub: DomainPermSub }) {
+	const permType = permSub.permission_type;
+	if (!permType) {
+		throw "permission_type was undefined";
+	}
+	
+	const [ testSub, testRes ] = useTestDomainPermissionSubscriptionMutation();
+	const onSubmit = (e) => {
+		e.preventDefault();
+		testSub(permSub.id);
+	};
+
+	// Function to map an item to a list entry.
+	function itemToEntry(perm: DomainPerm): ReactNode {
+		return (
+			<span className="text-cutoff entry perm-preview">
+				<strong>{ perm.domain }</strong>
+				{ perm.public_comment && <>({ perm.public_comment })</> }
+			</span>
+		);
+	}
+
+	return (
+		<>
+			<form
+				className="domain-permission-subscription-test"
+				onSubmit={onSubmit}
+			>
+				<h2>Test Subscription</h2>
+				Click the "test" button to instruct your instance to do a test
+				fetch and parse of the {permType} list at the subscription URI.
+				<br/>
+				If the fetch is successful, you will see a list of {permType}s
+				(or {permType} drafts) that *would* be created by this subscription,
+				along with the public comment for each {permType} (if applicable).
+				<br/>
+				The test does not actually create those {permType}s in your database.
+				<MutationButton
+					disabled={false}
+					label={"Test"}
+					result={testRes}
+				/>
+			</form>
+			{ testRes.data && "error" in testRes.data
+				? <div className="info perm-issue">
+					<i className="fa fa-fw fa-exclamation-circle" aria-hidden="true"></i>
+					<b>
+						The following issue was encountered when doing a fetch + parse:
+						<br/><code>{ testRes.data.error }</code>
+						<br/>This may be due to a temporary outage at the remote URL,
+						or you may wish to check your subscription settings and test again.
+					</b>
+				</div>
+				: <>
+					{ testRes.data && `${testRes.data?.length} ${permType}s would be created by this subscription:`}
+					<PageableList
+						isLoading={testRes.isLoading}
+						isSuccess={testRes.isSuccess}
+						items={testRes.data}
+						itemToEntry={itemToEntry}
+						isError={testRes.isError}
+						error={testRes.error}
+						emptyMessage={<b>No entries!</b>}
+					/>
+				</>
+			}
+		</>
+	);
+}