diff --git a/pipekit/repo.py b/pipekit/repo.py
index 266f7ad..4dc26f9 100644
--- a/pipekit/repo.py
+++ b/pipekit/repo.py
@@ -404,7 +404,8 @@ def clear_stale_locks(max_age_hours: int = 24, live_pids: set[int] | None = None
 def create_run(module_id: int, *, group_run_id: int | None = None) -> int:
     with db.connect() as c:
         cur = c.execute(
-            "INSERT INTO run_log (module_id, group_run_id) VALUES (?, ?)",
+            "INSERT INTO run_log (module_id, group_run_id, started_at) "
+            "VALUES (?, ?, datetime('now'))",
             (module_id, group_run_id),
         )
         return int(cur.lastrowid)
@@ -494,6 +495,10 @@ def list_runs(*, module_id: int | None = None, status: str | None = None,
     params.append(limit)
     with db.connect() as c:
         return [dict(r) for r in c.execute(
-            f"SELECT r.*, m.name AS module_name FROM run_log r "
+            f"SELECT r.*, m.name AS module_name, "
+            f"CASE WHEN r.started_at IS NOT NULL AND r.finished_at IS NOT NULL "
+            f"THEN CAST(ROUND((julianday(r.finished_at) - julianday(r.started_at)) * 86400) AS INTEGER) "
+            f"ELSE NULL END AS duration_s "
+            f"FROM run_log r "
             f"LEFT JOIN module m ON r.module_id=m.id "
             f"{clause} ORDER BY r.id DESC LIMIT ?", params)]
diff --git a/pipekit/web/app.py b/pipekit/web/app.py
index a46e4d2..77437d1 100644
--- a/pipekit/web/app.py
+++ b/pipekit/web/app.py
@@ -29,6 +29,18 @@ _WEB_DIR = Path(__file__).parent
 _templates = Jinja2Templates(directory=_WEB_DIR / "templates")
 
 
+def _fmt_duration(seconds) -> str:
+    if seconds is None:
+        return "—"
+    s = int(seconds)
+    if s < 60:
+        return f"{s}s"
+    return f"{s // 60}m {s % 60:02d}s"
+
+
+_templates.env.filters["duration"] = _fmt_duration
+
+
 def mount_web(app: FastAPI) -> None:
     """Attach HTML pages + /static onto a FastAPI app."""
     app.mount("/static", StaticFiles(directory=_WEB_DIR / "static"), name="static")
diff --git a/pipekit/web/templates/module_detail.html b/pipekit/web/templates/module_detail.html
index 29021b0..9f9b0a6 100644
--- a/pipekit/web/templates/module_detail.html
+++ b/pipekit/web/templates/module_detail.html
@@ -187,12 +187,13 @@
             <div class="body tight">
                 {% if recent_runs %}
                 <table class="grid">
-                    <thead><tr><th>id</th><th>started</th><th>status</th><th>rows</th></tr></thead>
+                    <thead><tr><th>id</th><th>started</th><th>duration</th><th>status</th><th>rows</th></tr></thead>
                     <tbody>
                     {% for r in recent_runs %}
                         <tr>
                             <td><a href="/runs/{{ r.id }}">#{{ r.id }}</a></td>
-                            <td class="mono">{{ r.started_at }}</td>
+                            <td class="mono">{{ r.started_at or '—' }}</td>
+                            <td class="mono">{{ r.duration_s | duration }}</td>
                             <td><span class="pill {{ r.status }}">{{ r.status }}</span></td>
                             <td class="mono">{{ r.row_count if r.row_count is not none else "—" }}</td>
                         </tr>
diff --git a/pipekit/web/templates/runs.html b/pipekit/web/templates/runs.html
index a99f2a4..102e840 100644
--- a/pipekit/web/templates/runs.html
+++ b/pipekit/web/templates/runs.html
@@ -22,7 +22,7 @@
                     <th style="width:5em">id</th>
                     <th>module</th>
                     <th>started</th>
-                    <th>finished</th>
+                    <th>duration</th>
                     <th style="width:8em">status</th>
                     <th style="width:7em">rows</th>
                     <th>error</th>
@@ -33,8 +33,8 @@
                 <tr>
                     <td><a href="/runs/{{ r.id }}">#{{ r.id }}</a></td>
                     <td><a href="/modules/{{ r.module_id }}">{{ r.module_name }}</a></td>
-                    <td class="mono">{{ r.started_at }}</td>
-                    <td class="mono">{{ r.finished_at or '—' }}</td>
+                    <td class="mono">{{ r.started_at or '—' }}</td>
+                    <td class="mono">{{ r.duration_s | duration }}</td>
                     <td><span class="pill {{ r.status }}">{{ r.status }}</span></td>
                     <td class="mono">{{ r.row_count if r.row_count is not none else "—" }}</td>
                     <td class="mono" style="max-width:22rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">{{ r.error or '' }}</td>