diff --git a/swh/web/common/archive.py b/swh/web/common/archive.py
--- a/swh/web/common/archive.py
+++ b/swh/web/common/archive.py
@@ -295,6 +295,21 @@
     )
 
 
+def lookup_origin_snapshots(origin: OriginInfo) -> List[str]:
+    """Return ids of the snapshots of an origin.
+
+    Args:
+        origin: origin's dict with 'url' key
+
+    Returns:
+        List of unique snapshot identifiers in hexadecimal format resulting
+        from the visits of the origin.
+    """
+    return [
+        snapshot.hex() for snapshot in storage.origin_snapshot_get_all(origin["url"])
+    ]
+
+
 def search_origin(
     url_pattern: str,
     use_ql: bool = False,
diff --git a/swh/web/tests/common/test_archive.py b/swh/web/tests/common/test_archive.py
--- a/swh/web/tests/common/test_archive.py
+++ b/swh/web/tests/common/test_archive.py
@@ -216,6 +216,14 @@
     assert actual_origin == expected_origin
 
 
+def test_lookup_origin_snapshots(archive_data, origin_with_multiple_visits):
+    origin_url = origin_with_multiple_visits["url"]
+    visits = archive_data.origin_visit_get(origin_url)
+
+    origin_snapshots = archive.lookup_origin_snapshots(origin_with_multiple_visits)
+    assert set(origin_snapshots) == {v["snapshot"] for v in visits}
+
+
 def test_lookup_release_ko_id_checksum_not_a_sha1(invalid_sha1):
     with pytest.raises(BadInputExc) as e:
         archive.lookup_release(invalid_sha1)