diff --git a/src/routes/LoginWithOAuthApp.tsx b/src/routes/LoginWithOAuthApp.tsx
index a51057da7..79d40e00d 100644
--- a/src/routes/LoginWithOAuthApp.tsx
+++ b/src/routes/LoginWithOAuthApp.tsx
@@ -15,7 +15,12 @@ import { Button } from '../components/fields/Button';
 import { FieldInput } from '../components/fields/FieldInput';
 import { AppContext } from '../context/App';
 import type { AuthOptions } from '../types';
-import { getNewOAuthAppURL } from '../utils/auth';
+import {
+  getNewOAuthAppURL,
+  isValidClientId,
+  isValidHostname,
+  isValidToken,
+} from '../utils/auth';
 import Constants from '../utils/constants';
 
 interface IValues {
@@ -35,25 +40,19 @@ export const validate = (values: IValues): IFormErrors => {
 
   if (!values.hostname) {
     errors.hostname = 'Required';
-  } else if (
-    !/^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$/i.test(
-      values.hostname,
-    )
-  ) {
+  } else if (!isValidHostname(values.hostname)) {
     errors.hostname = 'Invalid hostname.';
   }
 
   if (!values.clientId) {
-    // 20
     errors.clientId = 'Required';
-  } else if (!/^[A-Z0-9]{20}$/i.test(values.clientId)) {
+  } else if (!isValidClientId(values.clientId)) {
     errors.clientId = 'Invalid client id.';
   }
 
   if (!values.clientSecret) {
-    // 40
     errors.clientSecret = 'Required';
-  } else if (!/^[A-Z0-9]{40}$/i.test(values.clientSecret)) {
+  } else if (!isValidToken(values.clientSecret)) {
     errors.clientSecret = 'Invalid client secret.';
   }
 
diff --git a/src/routes/LoginWithPersonalAccessToken.tsx b/src/routes/LoginWithPersonalAccessToken.tsx
index 5fc1b6ac9..55726ed6f 100644
--- a/src/routes/LoginWithPersonalAccessToken.tsx
+++ b/src/routes/LoginWithPersonalAccessToken.tsx
@@ -15,7 +15,7 @@ import type { AuthTokenOptions } from '../types';
 import { Constants } from '../utils/constants';
 
 import { Button } from '../components/fields/Button';
-import { getNewTokenURL } from '../utils/auth';
+import { getNewTokenURL, isValidHostname, isValidToken } from '../utils/auth';
 
 interface IValues {
   token?: string;
@@ -32,17 +32,13 @@ export const validate = (values: IValues): IFormErrors => {
 
   if (!values.hostname) {
     errors.hostname = 'Required';
-  } else if (
-    !/^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$/i.test(
-      values.hostname,
-    )
-  ) {
+  } else if (!isValidHostname(values.hostname)) {
     errors.hostname = 'Invalid hostname.';
   }
 
   if (!values.token) {
     errors.token = 'Required';
-  } else if (!/^[A-Z0-9_]{40}$/i.test(values.token)) {
+  } else if (!isValidToken(values.token)) {
     errors.token = 'Invalid token.';
   }
 
diff --git a/src/utils/auth.test.ts b/src/utils/auth.test.ts
index e92ac835c..d2e904a74 100644
--- a/src/utils/auth.test.ts
+++ b/src/utils/auth.test.ts
@@ -167,4 +167,52 @@ describe('utils/auth.tsx', () => {
       ).toBeTruthy();
     });
   });
+
+  describe('isValidHostname', () => {
+    it('should validate hostname - github cloud', () => {
+      expect(auth.isValidHostname('github.com')).toBeTruthy();
+    });
+
+    it('should validate hostname - github enterprise server', () => {
+      expect(auth.isValidHostname('github.gitify.io')).toBeTruthy();
+    });
+
+    it('should invalidate hostname - empty', () => {
+      expect(auth.isValidHostname('')).toBeFalsy();
+    });
+
+    it('should invalidate hostname - invalid', () => {
+      expect(auth.isValidHostname('github')).toBeFalsy();
+    });
+  });
+
+  describe('isValidClientId', () => {
+    it('should validate client id - valid', () => {
+      expect(auth.isValidClientId('1234567890_ASDFGHJKL')).toBeTruthy();
+    });
+
+    it('should validate client id - empty', () => {
+      expect(auth.isValidClientId('')).toBeFalsy();
+    });
+
+    it('should validate client id - invalid', () => {
+      expect(auth.isValidClientId('1234567890asdfg')).toBeFalsy();
+    });
+  });
+
+  describe('isValidToken', () => {
+    it('should validate token - valid', () => {
+      expect(
+        auth.isValidToken('1234567890_asdfghjklPOIUYTREWQ0987654321'),
+      ).toBeTruthy();
+    });
+
+    it('should validate token - empty', () => {
+      expect(auth.isValidToken('')).toBeFalsy();
+    });
+
+    it('should validate token - invalid', () => {
+      expect(auth.isValidToken('1234567890asdfg')).toBeFalsy();
+    });
+  });
 });
diff --git a/src/utils/auth.ts b/src/utils/auth.ts
index fba2e2c01..62a052bac 100644
--- a/src/utils/auth.ts
+++ b/src/utils/auth.ts
@@ -167,3 +167,17 @@ export function getNewOAuthAppURL(hostname: string): string {
 
   return newOAuthAppURL.toString();
 }
+
+export function isValidHostname(hostname: string) {
+  return /^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$/i.test(
+    hostname,
+  );
+}
+
+export function isValidClientId(clientId: string) {
+  return /^[A-Z0-9_]{20}$/i.test(clientId);
+}
+
+export function isValidToken(token: string) {
+  return /^[A-Z0-9_]{40}$/i.test(token);
+}