Spotlight: XLSX — free diagnosis, paid cure for broken spreadsheets
Anyone who has inherited a spreadsheet from a former employee, a client, or a coworker three reorgs ago knows the specific dread of a workbook that looks fine and isn't. A formula references a cell that got deleted two tabs ago. A column of numbers is secretly text, so SUM returns zero. There's a hidden sheet nobody remembers making. Excel will not warn you about any of this. XLSX.com is built around that exact gap.
You upload an .xls, .xlsx, or .xlsm file (up to 20MB on the free tier) and it runs five checks: broken formula references, numbers stored as text, hidden sheets/rows/columns, external links to other workbooks, and volatile functions like NOW() and INDIRECT() that slow down recalculation. The scan gives you exact cell addresses, not vague warnings, and it's unlimited and free. If you want it to actually fix what it finds, unhiding sheets, stripping external links, converting text back to numbers, that's the $9/month Pro tier, with a preview before anything changes and a CSV export of what got altered.
The smart part isn't the checks themselves (any experienced Excel user could eyeball most of these given time). It's the split between diagnosis and treatment. The free tier is generous enough to be genuinely useful on its own: you can run it on every file you touch, no limit, and just fix things manually once you know where they are. That's a real value exchange, not a bait-and-switch trial. The paid tier only has to convince you that one-click fixes are worth $9/month over doing it yourself, which is an easy sell once you've spent twenty minutes hunting for a phantom hidden column in a 400-row sheet.
The other detail worth noting: they say the file never leaves your device, the scan runs in the browser. For anyone auditing a spreadsheet with client financials, payroll, or anything else they'd rather not upload to a third-party server, that's not a footnote, it's the reason they'd trust the tool at all.
This is for people who work with Excel files handed off between people: agencies delivering deliverables, ops and finance folks auditing inherited models, consultants doing spreadsheet cleanup before a handover, template sellers who want to make sure what they're shipping is clean. If you regularly get a spreadsheet from someone else and have to trust it before you build on it, this solves a real, recurring annoyance.
It is not for people working in Google Sheets (no mention of that here), and it's not a formula auditor in the deep sense, it won't tell you if your logic is wrong, only that certain structural things are broken. The 20MB free / 50MB Pro ceiling also means this isn't built for the truly enormous financial models some finance teams run. And if your spreadsheet problems are more about bad design than hidden gremlins, this tool won't touch that.
Where I'd guess this goes next: more checks (conditional formatting bloat, orphaned named ranges, circular references would all fit the pattern), batch scanning for teams handling multiple files at once, and probably a play for finance/ops teams as a seat-based product rather than a $9 individual subscription. The bundle of free converters and cheatsheets sitting alongside it (CSV to Excel, keyboard shortcuts, etc.) also reads like a content/SEO funnel feeding the audit tool, which is a reasonable way to get in front of people who are already knee-deep in someone else's spreadsheet.
Try XLSX: xlsx.com
See the launch: XLSX on welaunch.sh