diff --git a/static/iddiff.html b/static/iddiff.html
index 87f2f89..f23e773 100644
--- a/static/iddiff.html
+++ b/static/iddiff.html
@@ -150,6 +150,18 @@ <h1 class="text-center">IETF Author Tools - iddiff</h1>
             </div>
           </div>
         </div>
+        <div class="row mt-2">
+          <div>
+            <div class="form-check form-check-inline">
+              <input class="form-check-input" type="radio" name="switchDiffTool" id="switchRfcDiff" checked>
+              <label class="form-check-label" for="switchRfcDiff">Use rfcdiff</label>
+            </div>
+            <div class="form-check form-check-inline">
+              <input class="form-check-input" type="radio" name="switchDiffTool" id="switchIdDiff">
+              <label class="form-check-label" for="switchIdDiff">Use iddiff</label>
+            </div>
+          </div>
+        </div>
         <div class="row mt-2">
           <div class="d-grid gap-2 d-md-flex justify-content-md-center">
             <button class="btn btn-primary btn-lg flex-grow-1" type="button" value="compare" id="buttonCompare" data-title="Compare (side by side)" data-bs-toggle2="tooltip" data-bs-placement="bottom">Compare (side by side)</button>
diff --git a/static/scripts/iddiff.js b/static/scripts/iddiff.js
index 2b18fde..fc6e36b 100644
--- a/static/scripts/iddiff.js
+++ b/static/scripts/iddiff.js
@@ -16,6 +16,7 @@ const buttonOpen = document.getElementById('buttonOpen');
 const buttonShare = document.getElementById('buttonShare');
 const tabLinks = document.getElementsByClassName('tab-link');
 const switchRaw = document.getElementById('switchRaw');
+const switchIdDiff = document.getElementById('switchIdDiff');
 
 // enable Bootstrap/Popper tooltips
 var tooltipTriggerList = [].slice.call(document.querySelectorAll('[data-bs-toggle2="tooltip"]'));
@@ -137,6 +138,10 @@ function getShareableURL(button) {
     url += '&raw=1'
   }
 
+  if (switchIdDiff.checked) {
+    url += '&iddiff=1'
+  }
+
   return url;
 }
 
@@ -207,6 +212,9 @@ function compare(event) {
   if (switchRaw.checked) {
     formData.append('raw', 1);
   }
+  if (switchIdDiff.checked) {
+    formData.append('iddiff', 1);
+  }
 
   const apiCall = '/api/iddiff';