diff --git a/README.md b/README.md
index 54c3d7d..e7a9ca5 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,30 @@ https://stackoverflow.com/questions/7885785/using-openssl-to-get-the-certificate
 #### iOS
  - drag mycert.cer to Xcode project, mark your target and 'Copy items if needed'
  - (skip this if you are using certificate pinning) no extra step needed for public key pinning,  AFNetworking will extract the public key from the certificate. 
+ - Using `der` base64 encoded:
+   - Create `der` certificate:
+	   ```bash
+	   openssl x509 -in cert.pem -outform der | base64
+	   ```
+   - To validate:
+	   ```bash
+	   echo "BASE64_CERT" | base64 -d | openssl x509 -inform der -text -noout
+	   ```
+   - Sample on JS side 
+	   ```javascript
+      fetch("https://publicobject.com", {
+        method: "GET" ,
+        pkPinning: true,
+        sslPinning: {
+          certs: [
+            "MIIC2DCCAcCgAwIBAgIBATANBgkqh....",
+            "MIIGvjCCBaagAwIBAgIQD7YO9foj3...."
+          ] 
+        }
+      })
+	   ```
+     Notes: iOS uses Base64 `der` certificates, while Android uses public key pinning.
+
 
 #### Android
  -  Only if using certificate pinning : place your .cer files under src/main/assets/
diff --git a/ios/RNSslPinning/RNSslPinning.m b/ios/RNSslPinning/RNSslPinning.m
index 3179a72..dee01d6 100644
--- a/ios/RNSslPinning/RNSslPinning.m
+++ b/ios/RNSslPinning/RNSslPinning.m
@@ -217,6 +217,35 @@ -(void) performMultipartRequest: (AFURLSessionManager*)manager obj:(NSDictionary
     BOOL disableAllSecurity = [[obj objectForKey:@"disableAllSecurity"] boolValue];
     
     NSSet *certificates = [AFSecurityPolicy certificatesInBundle:[NSBundle mainBundle]];
+    NSDictionary *sslPinning = [obj objectForKey:@"sslPinning"];
+    NSArray<NSString *> *certs = nil;
+    NSMutableSet *certDataSet = [NSMutableSet set];
+    
+    if ([sslPinning isKindOfClass:[NSDictionary class]]) {
+        id certsValue = [sslPinning objectForKey:@"certs"];
+        if ([certsValue isKindOfClass:[NSArray class]]) {
+            BOOL allStrings = YES;
+            for (id item in (NSArray *)certsValue) {
+                if (![item isKindOfClass:[NSString class]]) {
+                    allStrings = NO;
+                    break;
+                }
+            }
+            if (allStrings) {
+                certs = (NSArray<NSString *> *)certsValue;
+            }
+        }
+    }
+
+    for (NSString *base64Cert in certs) {
+        NSData *certData = [[NSData alloc] initWithBase64EncodedString:base64Cert
+                                           options:NSDataBase64DecodingIgnoreUnknownCharacters];
+        if (certData) {
+            [certDataSet addObject:certData];
+        } else {
+            NSLog(@"⚠️ Failed to decode certificate.");
+        }
+    }
     
     // set policy (ssl pinning)
     if(disableAllSecurity){
@@ -225,7 +254,7 @@ -(void) performMultipartRequest: (AFURLSessionManager*)manager obj:(NSDictionary
         policy.allowInvalidCertificates = true;
     }
     else if (pkPinning){
-        policy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModePublicKey withPinnedCertificates:certificates];
+        policy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate withPinnedCertificates:certDataSet];
     }
     else{
         policy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeCertificate withPinnedCertificates:certificates];