Find every bad cell before it costs you.
A malformed email, a date in the wrong format, a blank where a value must be — one bad row can bounce an invoice, break an import, or blow a deadline. 9000 Spreadsheets catches them all.
Drop a spreadsheet, describe what correct looks like, and watch every bad cell light up — right in your browser. Nothing is uploaded to be checked.
Every failing cell underlined by rule, health per column — the real app view.
Try it on your kind of data
Pick a sheet that looks like yours
Each opens a small, deliberately messy sample with the matching checks already applied — the bad cells are lit up before you touch anything.
Invoice batch
A double-billed line, a 3-decimal amount and an invoice date decades in the future — the errors that bounce a payment run.
Try it →Customer list
Broken emails, a duplicate contact and an invisible trailing space — the junk that silently wrecks a mail merge.
Try it →Orders sheet
A malformed email, a ship date before the order and an impossible quantity — the rows that break an import.
Try it →Watch it work
See it in under a minute
From a messy file to a highlighted sheet and an exported error report.
How it works
Four steps, no setup
You don't need to know what "data validation" means. Just follow along.
Drop your file
Drag a CSV, TSV or Excel file (up to 15 MB) onto the page — or click to browse, or open the sample sheet.
Say what correct means
Click a column and pick conditions in plain English, let AI propose rules from your data, or apply a one-click rule pack.
Bad cells light up
Coloured underlines per rule, a health strip per column, and the plain-English reason when you hover any flagged cell.
Export the report
Send out an error report (CSV or Excel) listing every failing cell and why — hand it to whoever owns the data.
Why teams use it
Honest about what it does
Validates in your browser
Your file is parsed, checked and highlighted entirely on your machine — it isn't uploaded to be validated. The opt-in AI features send only column names, types and a capped sample of values, never whole rows.
Plain-English rules
Every rule reads as a sentence anyone on the team can audit — "Email must be a valid address", "Signed up must not be in the future" — with a live count of how many rows fail it.
AI proposes, you decide
"Check this sheet" reads your columns and drafts a set of rules, each with a live would-flag count. Nothing is applied until you say so — you add them one at a time or all at once.
From messy to exportable
Export an error report as CSV or Excel, save named rulesets to reuse next week, and on the Team plan share one rule library across the whole team.
Pricing