Workbook Optimizer
Make slow workbooks open and recalculate fast again.
Find and fix what makes a file sluggish: used ranges stretching to row a million, thousands of unique styles, orphaned defined names, unused shared strings and volatile formulas. Each finding comes with a one-click fix and an estimated saving.
- Price
- Free
- Your files
- Never uploaded
- Runs
- In your browser
or drag it here
.xlsx, .xlsm, .xls · up to 50 MB · processed locally, never uploaded
Excel and spreadsheet files only. Export from Google Sheets as .xlsx or .csv.
Files stay on your device
What it does well
- Used-range trimming that removes phantom rows and columns
- Style deduplication, often the single biggest win on old files
- Volatile formula and full-column reference reporting
How to use Workbook Optimizer
- 1
Upload the workbook that has become slow.
- 2
Review the findings, sorted by estimated impact.
- 3
Select the fixes you want to apply.
- 4
Download the optimised workbook.
Watch a walkthrough
Common problems and fixes
The file is still slow after optimising.
The bottleneck is probably calculation, not size. Check the volatile function and full-column reference findings and rework those formulas.
Conditional formatting disappeared.
Rules applied to entire columns are consolidated. Re-add them scoped to the real data range, which is faster anyway.
Frequently asked questions
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