By default, SmartStamp is purely forward-looking: it stamps the next qualifying edit to a watched column, not data that's already there. If you're adding a rule to a sheet with existing history — a log, an order list, a form-response tab — you usually want those rows stamped too. That's what backfill is for.
Set it up
- Extensions → SmartStamp → Settings, tab Configure.
- Set up the rule as usual: sheet, row range, edit column, stamp target and value, and any condition.
- Under Options, tick Also apply this to existing rows in the range now.
- Save.
Saving runs the backfill immediately: SmartStamp reads every row currently in the range, checks each one against the same condition (or, with no condition, whether the edit column simply isn't blank), and stamps the rows that qualify. A result line under the summary reports how many rows were checked and how many were stamped.
What backfill checks
- Respects the same condition as live edits — a row only gets stamped if it currently passes the rule's condition, exactly as a fresh edit to that cell would.
- Respects “Don't overwrite an existing stamp” — if that option is on, a row that already has a stamp is skipped, so re-running backfill after adding more rows won't disturb ones already stamped.
- Skips rows outside the sheet's current size and caps at 50,000 rows per range in one run — a larger dataset needs splitting into smaller ranges.
- Uses your own account as the editor for anything based on the
{email}token, since there's no real edit event during a backfill — only a live edit records the actual person who typed the value.
Backfill vs. a live edit
The two paths converge on the same result — the same stamp value, from the same condition logic — but a live edit fires the moment you type, while backfill is a one-time sweep you trigger by saving with the checkbox on. If you add more historical rows later (e.g. importing another batch), open the range again, tick the box, and save once more to sweep the new rows in.
Backfill your existing data
Set up a rule, tick one box, and every row you already have gets checked in one pass — no code, no re-editing by hand.
See how it works →