diff --git a/src/client/features/rank-tracking/RankTrackingConfigModal.tsx b/src/client/features/rank-tracking/RankTrackingConfigModal.tsx
index 9348120..fc9338b 100644
--- a/src/client/features/rank-tracking/RankTrackingConfigModal.tsx
+++ b/src/client/features/rank-tracking/RankTrackingConfigModal.tsx
@@ -10,7 +10,7 @@ import { Modal } from "@/client/components/Modal";
 import { getStandardErrorMessage } from "@/client/lib/error-messages";
 import { captureClientEvent } from "@/client/lib/posthog";
 import type { RankTrackingConfig } from "@/types/schemas/rank-tracking";
-import { normalizeDomain } from "@/types/schemas/domain";
+import { domainField, normalizeDomain } from "@/types/schemas/domain";
 import {
   depthToPages,
   pagesToDepth,
@@ -54,11 +54,11 @@ export function RankTrackingConfigModal({
   const [createdConfigId, setCreatedConfigId] = useState<string | null>(null);
 
   const createMutation = useMutation({
-    mutationFn: () =>
+    mutationFn: (normalizedDomain: string) =>
       createRankTrackingConfig({
         data: {
           projectId,
-          domain,
+          domain: normalizedDomain,
           devices,
           serpDepth,
           locationCode,
@@ -79,12 +79,12 @@ export function RankTrackingConfigModal({
   });
 
   const updateMutation = useMutation({
-    mutationFn: () =>
+    mutationFn: (normalizedDomain: string) =>
       updateRankTrackingConfig({
         data: {
           projectId,
           configId: existingConfig!.id,
-          domain,
+          domain: normalizedDomain,
           devices,
           serpDepth,
           locationCode,
@@ -109,10 +109,16 @@ export function RankTrackingConfigModal({
       toast.error("Please enter a domain");
       return;
     }
+    const parsedDomain = domainField.safeParse(domain);
+    if (!parsedDomain.success) {
+      toast.error("Please enter a valid domain");
+      return;
+    }
+    setDomain(parsedDomain.data);
     if (isEdit) {
-      updateMutation.mutate();
+      updateMutation.mutate(parsedDomain.data);
     } else {
-      createMutation.mutate();
+      createMutation.mutate(parsedDomain.data);
     }
   };
 
diff --git a/src/server/lib/dataforseoBacklinks.test.ts b/src/server/lib/dataforseoBacklinks.test.ts
index 2f4e1e0..1ca970b 100644
--- a/src/server/lib/dataforseoBacklinks.test.ts
+++ b/src/server/lib/dataforseoBacklinks.test.ts
@@ -105,6 +105,10 @@ describe("normalizeBacklinksTarget", () => {
       normalizeBacklinksTarget("https://user:pass@example.com/private"),
     );
   });
+
+  it("rejects hostnames with unrecognized public suffixes before provider calls", () => {
+    expectValidationError(() => normalizeBacklinksTarget("example.invalidtld"));
+  });
 });
 
 describe("fetchBacklinksSummaryRaw", () => {
diff --git a/src/server/lib/dataforseoBacklinksTarget.ts b/src/server/lib/dataforseoBacklinksTarget.ts
index 6613cf2..3fcc452 100644
--- a/src/server/lib/dataforseoBacklinksTarget.ts
+++ b/src/server/lib/dataforseoBacklinksTarget.ts
@@ -1,5 +1,6 @@
 import { AppError } from "@/server/lib/errors";
 import type { BacklinksLookupInput } from "@/types/schemas/backlinks";
+import { parse as parseTld } from "tldts";
 
 type NormalizedBacklinkTarget = {
   apiTarget: string;
@@ -47,6 +48,17 @@ export function normalizeBacklinksTarget(
     throw new AppError("VALIDATION_ERROR", "Target is invalid");
   }
 
+  const parsedHostname = parseTld(domainHostname, {
+    allowPrivateDomains: true,
+  });
+  if (
+    parsedHostname.isIp ||
+    !parsedHostname.publicSuffix ||
+    (parsedHostname.isIcann !== true && parsedHostname.isPrivate !== true)
+  ) {
+    throw new AppError("VALIDATION_ERROR", "Target is invalid");
+  }
+
   if (parsed.username || parsed.password) {
     throw new AppError(
       "VALIDATION_ERROR",
diff --git a/src/types/schemas/domain.ts b/src/types/schemas/domain.ts
index cde4360..5eb66ac 100644
--- a/src/types/schemas/domain.ts
+++ b/src/types/schemas/domain.ts
@@ -136,8 +136,15 @@ export const domainPagesPageRequestSchema = z.object({
   search: z.string().optional(),
 });
 
+const optionalSearchNumberParam = z.coerce.number().optional().catch(undefined);
+const optionalSearchPositiveIntParam = z.coerce
+  .number()
+  .int()
+  .positive()
+  .optional()
+  .catch(undefined);
 const filterStringParam = z.string().optional();
-const filterNumberParam = z.coerce.number().optional();
+const filterNumberParam = optionalSearchNumberParam;
 
 export const domainSearchSchema = z.object({
   domain: z.string().optional(),
@@ -146,15 +153,16 @@ export const domainSearchSchema = z.object({
   order: z.enum(domainSortOrders).optional(),
   tab: z.enum(domainTabs).optional(),
   search: z.string().optional(),
-  loc: z.coerce.number().int().positive().optional(),
-  page: z.coerce.number().int().positive().optional(),
+  loc: optionalSearchPositiveIntParam,
+  page: optionalSearchPositiveIntParam,
   size: z.coerce
     .number()
     .int()
     .refine((value) =>
       (DOMAIN_KEYWORDS_PAGE_SIZES as readonly number[]).includes(value),
     )
-    .optional(),
+    .optional()
+    .catch(undefined),
   include: filterStringParam,
   exclude: filterStringParam,
   minTraffic: filterNumberParam,
diff --git a/src/types/schemas/search-params.test.ts b/src/types/schemas/search-params.test.ts
index 6770a96..33f35b9 100644
--- a/src/types/schemas/search-params.test.ts
+++ b/src/types/schemas/search-params.test.ts
@@ -24,4 +24,18 @@ describe("search param boolean parsing", () => {
       subdomains: false,
     });
   });
+
+  it("drops invalid optional domain pagination params", () => {
+    const parsed = domainSearchSchema.parse({
+      page: "0",
+      size: "25",
+      loc: "not-a-location",
+    });
+
+    expect(parsed).toEqual({
+      page: undefined,
+      size: undefined,
+      loc: undefined,
+    });
+  });
 });