At the frontier of spreadsheet add-ins
Excel™ will not tell you that someone typed over the formula.
Eleven add-ins that read the grid the way an auditor would. They find the numbers that should have been calculated, the worksheets Copilot™ will read wrong, the links a workbook makes to files you cannot see, what changed since the last save, what the formula in front of you actually does, and the mess in the file somebody sent you.
Free tier on all twenty No trial clock 30-day refund
| B | C | D | |
|---|---|---|---|
| 4 | Q3 forecast — draft | ||
| 5 | Region | Units | Revenue |
| 6 | North | 120 | 3,600 |
| 7 | South | 140 | 4,200 |
| 8 | East | 90 | 2,700 |
| 9 | Total | 350 | 10,500 |
The whole problem
Two defects, and the workbook still totals correctly.
Nothing errors. Nothing turns red. The number that stopped being a formula keeps agreeing with the total until the day an input changes and it quietly does not. Hardcoded Value Detector finds each one, shows it in place, explains what it displaced — and puts the formula back.
Cell D7
−4200
+=C7*30
Undo is free in every tier, always. Nothing this add-in writes to your workbook is locked behind a payment.
Eleven add-ins
Same idea, different mess.
Each one reads a worksheet the way the person who has to use it would.
In Excel™
Hardcoded Value Detector
Numbers typed over formulas, and constants buried inside them — each shown in place, with the formula put back.
£3 / moor £25 / yrAI Readiness Scanner and Fixer
The merged cells, banner rows and text-numbers that make Copilot™'s answers wrong rather than absent.
£6 / moor £45 / yrTwo-File Reconciliation
Matches two tables on a key rather than on row order, and says exactly what does not agree and why.
£12 / moor £99 / yrChange Diff
What changed since the last save, formula first — telling a replaced formula apart from an input that simply moved.
£5 / moor £45 / yrImport Cleaner for Xero
Your Xero export, ready to use in Excel™ — and your upload, checked before it fails.
Freeor Pro at £4 / mo, £39 / yrStructure Flattener
A sent report, made a table: headers unmerged, subtotal rows removed, every section name carried onto its rows.
Freeor Pro at £3 / mo, £29 / yrUnit-aware Calculation Checker
Dimensional mistakes in an engineering sheet: a length added to an area, kN summed with N, a header that contradicts its own formula.
£49 / yrfree tier, no expiryExternal Link and Dependency Mapper
Every reference a workbook makes outside itself — including the ones inside defined names, validation lists and conditional formats that Edit Links never shows.
£30 / yrfree tier, no expiryCalculation Sign-Off and Lock
Sign off a calculation, lock it, and let anyone prove later that the logic has not changed — verifying is free for everyone, forever.
Freeor Pro at £60 / yr, £6 / moSelection-Scoped Formula Explainer
What the selected formula actually does, in the workbook's own column headers and defined names — and what will break it.
Freeor Pro at £29 / yr, £3.50 / moIn Google Sheets™
AI Readiness Scanner and Fixer
Why Gemini™, ChatGPT and Copilot™ answer wrong about a sheet — merged cells, banner rows, numbers stored as text — scored out of 100 and fixed.
Freeor Pro at £39 / yr, £4.50 / moImport Cleaner for Xero
Cleans a Xero export so Google Sheets™ can use it, and checks a sheet against Xero's import rules before you upload.
Freeor Pro at £39 / yr, £4 / moHardcoded Value Detector
Finds the numbers typed over formulas in a Google Sheet™ — the total that stopped updating, the magic number buried in a formula.
Freeor Pro at £25 / yr, £3 / moTwo-File Reconciliation
Reconciles two tables on a key rather than on row order, and says exactly what does not agree and why.
Freeor Pro at £99 / yr, £12 / moSheet Speed Checker
Where the seconds go — empty rows, imports, volatile formulas, conditional-format clutter — with the safe fixes one click away.
Freeor Pro at £29 / yr, £4 / moForm Response Cleaner
Splits checkbox answers into columns, shortens question headers, drops duplicates and test entries. The responses tab is never touched.
Freeor Pro at £25 / yr, £3 / moMail Merge Pre-flight Check
Catches Hi ,, broken fields, duplicates and typo'd addresses, and shows exactly what every recipient will get.
Freeor Pro at £29 / yr, £4 / moPersonal Data and Sharing Check
Finds names, emails, NI numbers, bank details and health data — on hidden tabs and in notes too — and shows who can already see it.
Freeor Pro at £39 / yr, £4.50 / moSeller Export Cleaner
Etsy, eBay and Vinted sales exports in one clean ledger: gross, fees, refunds and net by UK tax year.
Freeor Pro at £25 / yr, £5 / moShared Sheet Guardrails
Let people edit a Google Sheet™ without breaking it: lock the formulas, add the dropdowns, see what was typed over or sorted out of line.
Freeor Pro at £29 / yr, £4 / moAI Readiness Scanner and Fixer
Copilot™ answers anyway. That is the danger.
It does not refuse a badly-shaped sheet — it reads it wrong and answers with confidence. Every scan, every score and every explanation is free.
B4
A merged banner row sits above the headers. Copilot™ reads it as the header.
D7
A number sits where the column's formula pattern breaks. Worth a look before you ask Copilot™ anything.
C6:C8
Numbers stored as text. Copilot™ will not sum them, and will not say so.
Pricing
A free tier on all ten. No trial clock.
Every add-in does its real work before you pay for anything, and reversing what one wrote to your workbook is never the paid part. The two flagships are detailed here; the other eight are priced above.
Paddle is the merchant of record for every paid add-in here. Paddle takes the payment, issues the invoice and handles the tax, and is the seller named on your receipt. Prices exclude tax, calculated at checkout from your location. Subscriptions renew until cancelled, and cancelling is done through Paddle, from the receipt or at paddle.net. Full refund within 30 days of any payment, no reason needed — see the refund policy, the terms of service and the privacy notice.
Hardcoded Value Detector
£3 / mo · £25 / yr- Free: check and explain the active sheet. Undo.
- Paid: whole-workbook scan, guided fix, CSV and Markdown export.
AI Readiness Scanner and Fixer
£6 / mo · £45 / yr- Free: every scan, every score, every explanation. Restore.
- Paid: one-click fixes, and guided fixes that show the cells before writing.
Small, sharp spreadsheet add-ins
Open the sheet you least trust.
The free tier scans it, scores it and explains every finding before you decide anything. Undo is free, always.