diff --git a/static/app.js b/static/app.js
index dd32f2c..6e83f37 100644
--- a/static/app.js
+++ b/static/app.js
@@ -8,6 +8,7 @@ let clockOffset = 0;   // serverTime - clientTime
 let token = localStorage.getItem(TOKEN_KEY);
 let statsLoaded = false;
 let subscribed = false;
+let currentShareText = "";
 
 async function api(method, path, body) {
   const headers = { "Content-Type": "application/json" };
@@ -36,6 +37,45 @@ function formatPrecise(ms) {
   return `${formatMs(ms).slice(0, -3)}.${String(Math.max(0, ms) % 1000).padStart(3, "0")}`;
 }
 
+function updateShareLinks() {
+  if (!currentShareText) return;
+  const gameUrl = new URL(location.pathname, location.origin).href;
+  const facebookUrl = new URL("https://www.facebook.com/sharer/sharer.php");
+  facebookUrl.searchParams.set("u", gameUrl);
+  facebookUrl.searchParams.set("quote", currentShareText);
+  $("share-facebook").href = facebookUrl.href;
+
+  const xUrl = new URL("https://twitter.com/intent/tweet");
+  xUrl.searchParams.set("text", currentShareText);
+  xUrl.searchParams.set("url", gameUrl);
+  $("share-x").href = xUrl.href;
+
+  const blueskyUrl = new URL("https://bsky.app/intent/compose");
+  blueskyUrl.searchParams.set("text", `${currentShareText} ${gameUrl}`);
+  $("share-bluesky").href = blueskyUrl.href;
+
+  const instanceInput = $("mastodon-instance");
+  const mastodonLink = $("share-mastodon");
+  const shareError = $("share-error");
+  try {
+    const instance = new URL(instanceInput.value.trim());
+    if (instance.protocol !== "https:" || !instance.hostname || instance.username || instance.password) {
+      throw new Error("Enter an HTTPS Mastodon instance URL.");
+    }
+    const mastodonUrl = new URL("/share", instance.origin);
+    mastodonUrl.searchParams.set("text", `${currentShareText} ${gameUrl}`);
+    mastodonLink.href = mastodonUrl.href;
+    mastodonLink.removeAttribute("aria-disabled");
+    mastodonLink.tabIndex = 0;
+    shareError.textContent = "";
+  } catch {
+    mastodonLink.removeAttribute("href");
+    mastodonLink.setAttribute("aria-disabled", "true");
+    mastodonLink.tabIndex = -1;
+    shareError.textContent = "Enter an HTTPS Mastodon instance URL to enable sharing.";
+  }
+}
+
 function zoneFor(remaining) {
   return game.zones.find((z) => remaining > z.remaining_to_ms) ?? game.zones[game.zones.length - 1];
 }
@@ -200,11 +240,16 @@ async function loadStats() {
 $("the-button").addEventListener("click", async () => {
   const btn = $("the-button");
   btn.disabled = true;
+  $("share-controls").hidden = true;
+  currentShareText = "";
   try {
     const r = await api("POST", "/api/press");
     game.deadline = r.deadline;
+    currentShareText = `I pushed the button at ${formatPrecise(r.press.remaining_ms)}.`;
     $("press-result").textContent =
       `You pressed in the ${r.press.zone} zone with ${formatPrecise(r.press.remaining_ms)} remaining: +${r.press.points} points`;
+    updateShareLinks();
+    $("share-controls").hidden = false;
     await loadMe();
   } catch (e) {
     $("press-result").textContent = e.message;
@@ -214,6 +259,8 @@ $("the-button").addEventListener("click", async () => {
   }
 });
 
+$("mastodon-instance").addEventListener("input", updateShareLinks);
+
 $("register-form").addEventListener("submit", async (ev) => {
   ev.preventDefault();
   $("register-error").textContent = "";
diff --git a/static/index.html b/static/index.html
index c03cb8e..610de40 100644
--- a/static/index.html
+++ b/static/index.html
@@ -27,6 +27,20 @@
     <section id="button-section">
       <button id="the-button" class="zone-green" disabled>PRESS</button>
       <p id="press-result" aria-live="polite"></p>
+      <div id="share-controls" hidden>
+        <p>Share your press:</p>
+        <div class="share-links">
+          <a id="share-facebook" class="share-link" target="_blank" rel="noopener noreferrer">Facebook</a>
+          <a id="share-x" class="share-link" target="_blank" rel="noopener noreferrer">X</a>
+          <a id="share-bluesky" class="share-link" target="_blank" rel="noopener noreferrer">Bluesky</a>
+        </div>
+        <label for="mastodon-instance">Mastodon instance</label>
+        <div class="share-links">
+          <input id="mastodon-instance" type="url" value="https://mastodon.social" aria-label="Mastodon instance URL">
+          <a id="share-mastodon" class="share-link" target="_blank" rel="noopener noreferrer">Share on Mastodon</a>
+        </div>
+        <p id="share-error" class="error" aria-live="polite"></p>
+      </div>
     </section>
 
     <section id="register-section" hidden>
diff --git a/static/style.css b/static/style.css
index 63b5cf4..1a64957 100644
--- a/static/style.css
+++ b/static/style.css
@@ -102,6 +102,29 @@ input, form button {
   padding: 0.4rem 0.8rem;
 }
 
+.share-links {
+  display: flex;
+  flex-wrap: wrap;
+  justify-content: center;
+  align-items: center;
+  gap: 0.5rem;
+  margin: 0.5rem 0 1rem;
+}
+
+.share-link {
+  display: inline-block;
+  padding: 0.45rem 0.8rem;
+  border: 1px solid #bbb;
+  border-radius: 4px;
+  color: #fff;
+  text-decoration: none;
+}
+
+.share-link:hover, .share-link:focus-visible { background: #666; }
+.share-link[aria-disabled="true"] { opacity: 0.5; pointer-events: none; }
+#mastodon-instance { max-width: 100%; }
+#share-controls label { display: block; }
+
 .error { color: var(--red); }
 
 #rules { text-align: left; font-size: 0.9rem; color: #ccc; }