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SPREADSHEET ERROR CHECKER

A spreadsheet error checker for the issues Excel won't show you.

SaferSheets is a spreadsheet error checker that goes past the visible #REF! and #DIV/0! cells. It surfaces the silent issues — bad ranges, stale references, hidden sheets, structural drift — that make a workbook look fine and behave wrong. Works on Excel and Google Sheets.

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Free tier — 30 audits/month — no card required.

Visible errors are only half the problem

Excel and Google Sheets both highlight the obvious cell-level errors with red marks: #REF!, #DIV/0!, #VALUE!, #NAME?. You can fix those by going through them one at a time.

What neither tool surfaces: a SUM that excludes one row because somebody hid it. A VLOOKUP that's pointing at a renamed sheet and silently returning #N/A but the cell is formatted to display "—" so nobody notices. A percentage column where two of fifty rows are formatted as decimals. A spreadsheet error checker built for catching these — not just the visible ones — is the whole point of SaferSheets.

How the error check runs

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    1. Upload or pick from Drive

    Drop an .xlsx or pick a Google Sheet. The error checker runs the same checks regardless of source.

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    2. Multi-layer analysis

    Each layer — formulas, data, structure, formatting — is analyzed in parallel. Issues are tagged by category so you can fix in batches.

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    3. Severity ranking

    Critical (will break a downstream calculation) at the top. Soft warnings (looks suspicious but might be intentional) at the bottom.

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    4. Cell-level explanations

    Every issue tells you what's wrong, why it matters, and how to fix it — with the actual formula syntax or cell reference.

What the error checker flags

Eight categories of issues across formula integrity, data quality, structure, and hidden risk. The full list is generated for every workbook; here are the patterns you'll see most often.

  • Hard error cells

    #REF!, #DIV/0!, #VALUE!, #N/A, #NAME?, #NUM!, #NULL!, #SPILL!, #CALC! — listed by cell address with the originating formula and the likely root cause.

  • Silent broken lookups

    VLOOKUP / INDEX-MATCH formulas that return a result, but the lookup target has moved or been renamed since the formula was written. The cell shows a value, but the wrong one.

  • Out-of-sync ranges

    Half the column-totals sum A1:A100, the other half A1:A99 or A1:A105. Easy to miss visually; catastrophic when a new row is added below row 99.

  • Percent / decimal mismatch

    Two columns multiplied together where one is formatted as a percentage and the other as a decimal — produces a number that's off by a factor of 100.

  • Header rows in the wrong place

    A header row pasted into the middle of the data instead of the top. Breaks pivots, breaks sorts, breaks any formula relying on column position.

  • Conditional-format conflicts

    Multiple overlapping rules where one color hides another, or where the rule references a deleted range and silently does nothing.

  • Stale external references

    Cells linking to other workbooks that haven't been updated since the source moved. Excel shows the last-cached value; the spreadsheet error checker flags the staleness.

  • Inconsistent number formats

    A spreadsheet error checker also surfaces presentation-level inconsistencies — currency mixed with decimal, two date formats in one column, scientific notation creeping in.

Frequently asked questions

What kinds of spreadsheet errors does this find that Excel doesn't?

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Excel's built-in checker catches visible errors. SaferSheets adds: silent broken lookups (formula returns a value, but the wrong one), inconsistent ranges across formulas, percent/decimal multiplication mismatches, hardcoded numbers buried in SUMs, hidden sheets and rows, and external references pointing at files that no longer exist. The categories overlap with what an external auditor would check, automated.

Does the error checker work on .csv files too?

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Yes for data-quality checks (mixed formats, outliers, header detection). CSV files don't have formulas or multiple sheets, so the formula-integrity and structural checks don't apply. The applicable subset still runs.

How is this different from a standard Excel auditor's review?

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A human auditor adds judgment — they can tell whether a hardcoded $5000 is a fudge factor or a legitimate constant. The error checker surfaces every candidate so the auditor focuses on the judgment calls instead of the click-by-click discovery. Many auditors use SaferSheets as a pre-screen, then review the flagged items by hand.

Can I run the error check on someone else's spreadsheet?

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Yes — as long as they shared it with you or you have the file. The check is read-only and produces a corrected copy that you can send back. The original file is never modified.

Will it run on large workbooks?

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Free tier audits files up to 10 MB; Pro raises that to 50 MB. Files larger than 50 MB are unusual in practice — usually they have hundreds of tabs or hundreds of thousands of rows. If you have one, contact support and we'll work something out.

Further reading

Deep-dives from the SaferSheets blog

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