New in XLKeys: Cell Capacity and Workbook Performance Scans

A few weeks ago, I wrote about how to troubleshoot Google Sheets spreadsheets that break or have poor performance. Most of the fixes are pretty simple once you know what is wrong. The hard part is finding the problem in a workbook with 20 tabs, thousands of formulas, and years of old work piled into it.

That is the problem I wanted to make easier, so I added two new tools to the Workbook Health section in XLKeys: the Cell Capacity Audit and the Performance Audit. Neither one tries to change your workbook for you. They are meant to point you toward the tabs and formulas worth checking first.

The Problem: A Slow Spreadsheet Does Not Tell You Why

When a spreadsheet starts acting up, the symptoms are usually obvious: typing lags, the loading bar keeps spinning, formulas take too long to update, or Sheets refuses to add more rows because the file is near its cell limit. What Sheets does not give you is a useful workbook-level report explaining where to look.

• A tab can look mostly empty while thousands of unused rows and columns still count toward the workbook limit.
• One slow formula is rarely the issue. It is usually a formula pattern repeated hundreds or thousands of times.
• Large workbooks make it hard to know where to start, so people end up deleting tabs or rewriting formulas at random.

The new scans turn those broad problems into a much shorter list of places to investigate.

Cell Capacity Audit: Find Out Where Your 10 Million Cells Went

Google Sheets allows up to 10,000,000 allocated cells in one spreadsheet. That total includes the full grid on every tab, not just cells with data in them. A sheet with 100 rows of real data and 50,000 allocated rows can quietly use a huge part of the limit.

The new Cell Capacity Audit shows your total allocated cells, how many cells remain, and how much each tab contributes. It also looks for blank rows and columns after your data and estimates how much space you may be able to recover.

• See the exact cell count and remaining room for the whole workbook.
• Sort the workbook by tab so oversized sheets are easy to spot.
• Find trailing blank rows and columns that may no longer be needed.
• Keep a 50-row and 5-column buffer after the last detected data so the suggestions are not too aggressive.

Performance Audit: Start With the Formulas Most Likely to Be Slow

The Performance Audit scans formulas across the workbook and groups the patterns that are commonly tied to slow recalculation. It ranks the results by likely impact, explains why each pattern can be expensive, and gives you sample cells you can click to inspect.

• External data formulas such as IMPORTRANGE, IMPORTXML, and GOOGLEFINANCE.
• Open-ended references such as A:A or A:B that scan every allocated row.
• Volatile or dynamic functions such as INDIRECT, OFFSET, NOW, TODAY, and RAND.
• Large arrays, repeated lookups, heavy text or REGEX work, and deeply nested formulas.
• Complex formulas that have been copied across many rows.

The point is not to tell you that every flagged formula is bad. Sometimes an IMPORTRANGE or an open-ended range is exactly what you need. The scan just helps you see where those patterns are concentrated so you can decide whether they are worth cleaning up.

How to Run the New Scans

Open the Google Sheets workbook you want to check, then run either tool from the keyboard:

• Cell Capacity Audit: press Alt, then A, W, C. On a Mac, use Option, then A, W, C.
• Performance Audit: press Alt, then A, W, P. On a Mac, use Option, then A, W, P.

XLKeys inspects only the workbook you authorize. The data is processed in your browser or through direct authenticated requests to the Google Sheets API, and spreadsheet contents are not sent to XLKeys servers or third parties.

My goal with both tools is pretty simple: when a workbook feels broken, you should not have to spend an afternoon guessing why. These scans will not fix every slow spreadsheet automatically, but they should give you a much better place to start.