diff --git a/src/form.css b/src/form.css
index 562c7a0..200476e 100644
--- a/src/form.css
+++ b/src/form.css
@@ -52,9 +52,13 @@ textarea {
   border: .2rem solid #b7b7b7;
   border-radius: .2rem;
   display: block;
-  margin: 0 0 1.2rem 0;
+  margin: 0 0 var(--gap-half) 0;
   padding: var(--padding);
 }
+label.number,
+input[type="range"] {
+  margin: 0 0 var(--gap) 0;
+}
 input[type="number"]:focus,
 input[type="password"]:focus,
 input[type="text"]:focus,
@@ -194,9 +198,6 @@ label.number {
   gap: var(--gap);
   padding: 0;
 }
-* + label.number {
-  margin: var(--gap) 0 0 0;
-}
 label.number span {
   flex-grow: 1;
   padding: 0 0 0 var(--padding);
diff --git a/src/index.html b/src/index.html
index 31493a0..333f00c 100644
--- a/src/index.html
+++ b/src/index.html
@@ -84,6 +84,14 @@
             </div>
           </form>
           <form action="#" name="options">
+            <label for="filterDifficulty">
+               difficulty filter<br>
+              <small>
+                hide text notes with mining proof lower
+                than:&nbsp;<span data-display="filter_difficulty"></span>. a zero value shows all notes.
+              </small>
+            </label>
+            <input type="range" name="filter_difficulty" step="1" min="0" max="32" id="filterDifficulty" value="0">
             <label class="number" for="miningTarget">
               <span>
                 mining difficulty<br>
@@ -94,7 +102,7 @@
                   <a href="https://github.com/nostr-protocol/nips/blob/master/13.md" target="_blank" rel="noopener noreferrer">proof of work (nip-13)</a>.
                 </small>
               </span>
-              <input type="number" name="mining_target" step="1" min="0" max="256" id="miningTarget" value="16">
+              <input type="number" name="mining_target" step="1" min="0" max="32" id="miningTarget" value="16">
             </label>
             <label class="number" for="miningTimeout">
               <span>
diff --git a/src/main.js b/src/main.js
index 59062e3..dc85c1e 100644
--- a/src/main.js
+++ b/src/main.js
@@ -324,7 +324,9 @@ const sortByCreatedAt = (evt1, evt2) => {
 };
 
 function renderFeed() {
-  const sortedFeeds = textNoteList.sort(sortByCreatedAt).reverse();
+  const sortedFeeds = textNoteList
+    .filter(note => !fitlerDifficulty || note.tags.some(([tag, , commitment]) => tag === 'nonce' && commitment >= fitlerDifficulty))
+    .sort(sortByCreatedAt).reverse();
   sortedFeeds.forEach((evt, i) => {
     if (feedDomMap[evt.id]) {
       // TODO check eventRelayMap if event was published to different relays
@@ -340,6 +342,13 @@ function renderFeed() {
   });
 }
 
+function rerenderFeed() {
+  Object.keys(feedDomMap).forEach(key => delete feedDomMap[key]);
+  Object.keys(replyDomMap).forEach(key => delete replyDomMap[key]);
+  feedContainer.replaceChildren([]);
+  renderFeed();
+}
+
 setInterval(() => {
   document.querySelectorAll('time[datetime]').forEach(timeElem => {
     timeElem.textContent = formatTime(new Date(timeElem.dateTime));
@@ -516,7 +525,9 @@ function handleRecommendServer(evt, relay) {
   if (textNoteList.length < 2) {
     feedContainer.append(art);
   } else {
-    const closestTextNotes = textNoteList.sort(sortEventCreatedAt(evt.created_at));
+    const closestTextNotes = textNoteList
+      .filter(note => !fitlerDifficulty || note.tags.some(([tag, , commitment]) => tag === 'nonce' && commitment >= fitlerDifficulty))
+      .sort(sortEventCreatedAt(evt.created_at));
     feedDomMap[closestTextNotes[0].id].after(art);
   }
   feedDomMap[evt.id] = art;
@@ -758,6 +769,18 @@ function hideNewMessage(hide) {
   newMessageDiv.hidden = hide;
 }
 
+let fitlerDifficulty = JSON.parse(localStorage.getItem('filter_difficulty')) ?? 0;
+const filterDifficultyInput = document.querySelector('#filterDifficulty');
+const filterDifficultyDisplay = document.querySelector('[data-display="filter_difficulty"]');
+filterDifficultyInput.addEventListener('input', (e) => {
+  localStorage.setItem('filter_difficulty', filterDifficultyInput.valueAsNumber);
+  fitlerDifficulty = filterDifficultyInput.valueAsNumber;
+  filterDifficultyDisplay.textContent = filterDifficultyInput.value;
+  rerenderFeed();
+});
+filterDifficultyInput.value = fitlerDifficulty;
+filterDifficultyDisplay.textContent = filterDifficultyInput.value;
+
 // arbitrary difficulty default, still experimenting.
 let difficulty = JSON.parse(localStorage.getItem('mining_target')) ?? 16;
 const miningTargetInput = document.querySelector('#miningTarget');