diff --git a/bincio/edit/server.py b/bincio/edit/server.py
index e603d1f..ec28198 100644
--- a/bincio/edit/server.py
+++ b/bincio/edit/server.py
@@ -716,8 +716,6 @@ async def strava_callback(code: str = "", error: str = "") -> RedirectResponse:
         token = exchange_code(strava_client_id, strava_client_secret, code)
     except StravaError:
         return RedirectResponse(f"{site_url}?strava=error")
-    # Stamp last_sync_at at connect time so the first sync only fetches new activities
-    token.setdefault("last_sync_at", int(time.time()))
     save_token(dd, token)
     return RedirectResponse(f"{site_url}?strava=connected")
 
@@ -787,4 +785,50 @@ async def strava_sync() -> JSONResponse:
     token["last_sync_at"] = int(time.time())
     save_token(dd, token)
 
-    return JSONResponse({"ok": True, "imported": imported, "skipped": skipped, "errors": errors[:5]})
+    return JSONResponse({"ok": True, "imported": imported, "skipped": skipped, "error_count": len(errors), "errors": errors[:5]})
+
+
+@app.post("/api/strava/reset")
+async def strava_reset(request: Request) -> JSONResponse:
+    """Reset last_sync_at.
+
+    mode=soft  — set to the started_at of the most recent activity already on disk
+                 (next sync only fetches activities newer than the last known one)
+    mode=hard  — clear last_sync_at entirely
+                 (next sync re-downloads the full Strava history, skipping existing files)
+    """
+    dd = _get_data_dir()
+    from bincio.extract.strava_api import load_token, save_token
+    token = load_token(dd)
+    if token is None:
+        raise HTTPException(400, "Not connected to Strava")
+
+    body = await request.json()
+    mode = body.get("mode", "soft")
+
+    if mode == "hard":
+        token.pop("last_sync_at", None)
+        save_token(dd, token)
+        return JSONResponse({"ok": True, "mode": "hard", "last_sync_at": None})
+
+    # soft: find the most recent started_at in the current index
+    from datetime import datetime, timezone
+    index_path = dd / "index.json"
+    last_ts: int | None = None
+    if index_path.exists():
+        index_data = json.loads(index_path.read_text(encoding="utf-8"))
+        started_ats = [
+            a.get("started_at") for a in index_data.get("activities", [])
+            if a.get("started_at")
+        ]
+        if started_ats:
+            latest = max(started_ats)
+            dt = datetime.fromisoformat(latest.replace("Z", "+00:00"))
+            last_ts = int(dt.astimezone(timezone.utc).timestamp())
+
+    if last_ts is None:
+        token.pop("last_sync_at", None)
+    else:
+        token["last_sync_at"] = last_ts
+    save_token(dd, token)
+    return JSONResponse({"ok": True, "mode": "soft", "last_sync_at": last_ts})
diff --git a/site/src/layouts/Base.astro b/site/src/layouts/Base.astro
index 3d17273..274b48a 100644
--- a/site/src/layouts/Base.astro
+++ b/site/src/layouts/Base.astro
@@ -204,6 +204,18 @@ const baseUrl = import.meta.env.BASE_URL ?? '/';
               id="strava-sync-btn"
               class="w-full py-2 px-4 rounded-lg font-medium text-sm bg-zinc-700 hover:bg-zinc-600 text-white transition-colors mt-2"
             >Sync now</button>
+            <div class="flex gap-2 mt-1">
+              <button
+                id="strava-reset-soft-btn"
+                class="flex-1 py-1.5 px-3 rounded-lg text-xs bg-zinc-800 hover:bg-zinc-700 text-zinc-400 hover:text-zinc-200 transition-colors"
+                title="Set sync point to your most recent activity — next sync only fetches newer ones"
+              >Reset</button>
+              <button
+                id="strava-reset-hard-btn"
+                class="flex-1 py-1.5 px-3 rounded-lg text-xs bg-zinc-800 hover:bg-zinc-700 text-zinc-400 hover:text-zinc-200 transition-colors"
+                title="Clear sync point — next sync re-checks all Strava activities"
+              >Hard reset</button>
+            </div>
           </div>
           <p id="strava-status" class="mt-3 text-xs text-center" style="min-height: 1.25rem"></p>
         </div>
@@ -262,7 +274,9 @@ const baseUrl = import.meta.env.BASE_URL ?? '/';
       const stravaConnect = document.getElementById('strava-connect-area');
       const stravaSync    = document.getElementById('strava-sync-area');
       const stravaConnBtn = document.getElementById('strava-connect-btn');
-      const stravaSyncBtn = document.getElementById('strava-sync-btn');
+      const stravaSyncBtn       = document.getElementById('strava-sync-btn');
+      const stravaResetSoftBtn  = document.getElementById('strava-reset-soft-btn');
+      const stravaResetHardBtn  = document.getElementById('strava-reset-hard-btn');
       const stravaLastSync = document.getElementById('strava-last-sync');
       const stravaChooseSub = document.getElementById('strava-choose-sub');
 
@@ -406,7 +420,8 @@ const baseUrl = import.meta.env.BASE_URL ?? '/';
           if (!r.ok) throw new Error(await r.text());
           const d = await r.json();
           stravaLastSync.textContent = new Date().toLocaleString();
-          stravaStatus.textContent = `Done — ${d.imported} imported, ${d.skipped} already up to date.`;
+          const errNote = d.error_count ? `, ${d.error_count} errors` : '';
+          stravaStatus.textContent = `Done — ${d.imported} imported, ${d.skipped} already up to date${errNote}.`;
           stravaStatus.style.color = '#4ade80';
           if (d.imported > 0) setTimeout(() => window.location.reload(), 1500);
         } catch (e) {
@@ -418,6 +433,36 @@ const baseUrl = import.meta.env.BASE_URL ?? '/';
         }
       });
 
+      async function stravaReset(mode) {
+        const btn = mode === 'soft' ? stravaResetSoftBtn : stravaResetHardBtn;
+        btn.disabled = true;
+        stravaStatus.textContent = '';
+        try {
+          const r = await fetch(`${editUrl}/api/strava/reset`, {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ mode }),
+          });
+          if (!r.ok) throw new Error(await r.text());
+          const d = await r.json();
+          if (mode === 'hard') {
+            stravaStatus.textContent = 'Hard reset done — next sync will re-check all activities.';
+          } else {
+            const date = d.last_sync_at ? new Date(d.last_sync_at * 1000).toLocaleDateString('en-GB', { day: 'numeric', month: 'short', year: 'numeric' }) : 'none';
+            stravaStatus.textContent = `Reset to ${date} — next sync fetches only newer activities.`;
+          }
+          stravaStatus.style.color = '#a1a1aa';
+        } catch (e) {
+          stravaStatus.textContent = 'Error: ' + e.message;
+          stravaStatus.style.color = '#f87171';
+        } finally {
+          btn.disabled = false;
+        }
+      }
+
+      stravaResetSoftBtn.addEventListener('click', () => stravaReset('soft'));
+      stravaResetHardBtn.addEventListener('click', () => stravaReset('hard'));
+
       // Handle ?strava= param set by the callback redirect (popup scenario)
       const sp = new URLSearchParams(window.location.search);
       if (sp.has('strava')) {