📊 SheetForge

A spreadsheet that keeps your numbers on your computer — a big growing grid, real formulas, and real .xlsx files in and out.

$29 one-time price. No subscription. Yours forever.

Buy Now — $29

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What's included: the full SheetForge app for Windows · one license covers 3 computers (free a slot anytime from inside the app with its "Deactivate" button, or from your CertSight account page by regenerating your key) · your license key is emailed at checkout and can also be shown on screen right after payment.

What it does

• A grid that grows with you. The sheet opens at 1,000 rows × 52 columns and grows as you work — columns continue all the way to ZZ. A formula bar shows and edits the selected cell's contents. No ribbon, no menus to dig through — click a cell and type.
• Real formulas. A cell holds a number, text, or a formula that starts with =. Formulas do arithmetic (+ − * / and parentheses), cell references and ranges (like A1:B5), and 29 functions — SUM, AVERAGE, COUNT, MIN, MAX, IF, IFERROR, SUMIF, COUNTIF, AVERAGEIF, VLOOKUP, INDEX, MATCH, ROUND, ABS, INT, SQRT, POWER, MOD, CONCAT, LEFT, RIGHT, MID, LEN, UPPER, LOWER, TODAY, NOW, and DATE — with simple comparisons (=, <, >, <=, >=, <>) inside IF. Values recalculate as you edit.
• Errors are shown, not hidden. A bad formula doesn't crash the sheet — the cell shows why: #DIV/0! for division by zero, #CYCLE! for a circular reference, #ERROR! for a formula it can't parse.
• Open real .xlsx — formulas included. "Open .xlsx" reads a genuine Excel workbook and brings its formulas in (through the SheetJS library), recomputed on open, so a workbook from Excel, Google Sheets, or LibreOffice keeps working as a living sheet, not a snapshot of numbers.
• Save .xlsx with formulas preserved. "Save .xlsx" writes a genuine Excel workbook that keeps your formulas, so the file opens correctly in Excel, Google Sheets, or LibreOffice and keeps calculating there.
• .csv and .json too. "Save .csv" writes computed values as plain comma-separated text with proper quoting, "Open CSV…" reads a .csv file into the grid, and SheetForge can save and reopen its own .json cell files. Files are read and written only through your system's open/save dialogs, on your own drives.
• Number formats and bold. Give a cell a currency, percent, or 2-decimals number format — the format persists when you save .xlsx. A bold toggle marks cells in JSON saves.
• Deactivate from inside the app. A "Deactivate" button in the toolbar frees that computer's activation slot when you replace a machine — no support ticket, no waiting.
• Everything stays on your computer. No cloud sync, no collaboration, no AI. The only requests SheetForge ever makes to CertSight are the activation and deactivation checks. No telemetry.

⚠️ Scope notes — read before you buy

• One sheet per file. SheetForge works on a single sheet. If you open a multi-sheet workbook, only the first sheet opens — and the app tells you that's what happened rather than silently dropping the rest.
• Bold doesn't survive .xlsx. The bold toggle persists in SheetForge's own JSON saves, but not in .xlsx saves — a workbook saved as .xlsx comes back without the bold. (Number formats DO persist to .xlsx.)
• Dates show as serial numbers. Date values display as Excel serial numbers (the raw count Excel stores), not as formatted dates.
• No sort, filter, charts, or macros. There is no sort/filter, no charts or graphs, no pivot tables, no macros, and no print command. The feature list above is the whole app.
• Windows only for now. The download below is a Windows portable build. There is no macOS or Linux build yet — we'd rather say that plainly than promise one. Your license will work on those builds if and when they're published.
• Human GUI click-through is still pending. Checkout, licensing, and activation are covered end to end by automated tests, but the app's hands-on flows have not yet had a full human play-through on a real Windows machine — we will say so plainly until that pass is done.

If any of the above is a deal-breaker for you, this isn't for you yet — and we'd rather tell you now than after checkout.

Download

Windows 10/11 (64-bit), portable build — no installer, just download and run.

macOS and Linux are not available yet. There is no build for them today; if one is published later, this same license key will activate it.

The app is unsigned, so Windows SmartScreen may show a warning on first launch — this is normal for a new publisher. Choose "More info → Run anyway" to start it.

How activation works: at checkout your license key is emailed to you (and can be shown on screen right after payment). Enter it on the app's activation screen — one license activates on up to 3 computers, with 30-day offline trust after activation. Replacing a computer? Use "Deactivate" inside the app to free its slot, or generate a fresh key from your account page (the old key stops working).