How they compare
| Feature | Microsoft Excel | Viztab |
|---|---|---|
| Row limit | 1,048,576 rows (hard limit) | 10,000,000+ rows |
| Column limit | 16,384 columns (XFD) | No fixed limit |
| File size limit | Crashes on large files (~500 MB+) | 2 GB+ tested |
| Speed with 500K rows | Slow to open, sluggish scrolling | Opens in seconds, smooth scrolling |
| Install required | Yes — desktop app or Office Online | No — runs in any browser |
| Data privacy | Local (desktop) or OneDrive (365) | Always local, never uploaded |
| Formulas | 500+ functions | 370+ functions |
| Macros & VBA | Full VBA support | Not supported |
| Price | $99.99/yr (Microsoft 365 Personal) | Free tier + affordable Pro |
| Platform | Windows, macOS, web (limited) | Any browser + desktop app |
Excel's 1-million-row wall
Since Excel 2007, the maximum number of rows in a worksheet has been fixed at 1,048,576. This is a hard limit built into the XLSX file format itself. If your CSV has 2 million rows, Excel will silently truncate it, loading only the first million and discarding the rest without warning.
Even below that limit, Excel struggles. Opening a file with 500,000 rows can take minutes, scrolling is laggy, and applying formulas across large ranges can freeze the application entirely. With complex workbooks, Excel's memory usage can spike to several gigabytes.
Viztab has no fixed row limit. Its streaming architecture loads and indexes data progressively, so a 10-million-row file opens in seconds and scrolls smoothly. You see the first rows almost instantly while the rest loads in the background.
No install, no subscription
Excel requires either a desktop installation (part of Microsoft 365 at $99.99/year for Personal or $149.99/year for Family) or the free but limited Excel Online. Setting up Excel on a new machine means downloading gigabytes of software, signing in with a Microsoft account, and managing license activations.
Viztab runs in any modern browser. Navigate to the app, drag in your file, and start working. There is nothing to install, no account required, and no subscription to manage. A desktop app is also available if you prefer a native window.
Privacy by default
The desktop version of Excel processes files locally, but Microsoft 365 increasingly pushes users toward OneDrive and cloud-based storage. AutoSave defaults to syncing files to the cloud, and many enterprise deployments require it.
With Viztab, your data never leaves your device under any circumstances. There is no cloud sync, no telemetry on your spreadsheet contents, and no account linking. For sensitive data — financial records, medical data, proprietary business information — this is a meaningful advantage.
When Excel is the better choice
Excel remains the gold standard for complex financial modeling, VBA macros, pivot tables, and deep enterprise integrations. If your workflow depends on Power Query, Power Pivot, or custom VBA scripts, Excel is irreplaceable. It also has the most extensive formula library of any spreadsheet application.
But if your primary need is opening, viewing, and analyzing large data files — especially CSVs and exports that exceed Excel's row limit — Viztab does the job faster, cheaper, and without artificial limits.
Frequently asked questions
Yes. Viztab supports both XLSX and CSV file formats. You can open your existing Excel files directly in Viztab without any conversion. You can also export your work back to XLSX format.
The limit comes from the XLSX file format specification, which uses 20 bits for row addressing (2^20 = 1,048,576). This was set in Excel 2007 and has not changed since. Earlier versions of Excel had an even lower limit of 65,536 rows.
For data viewing, analysis, and basic spreadsheet work, yes. Viztab supports 370+ formulas, sorting, filtering, and multi-tab workbooks. However, if you rely heavily on VBA macros, pivot tables, or Power Query, you will still need Excel for those features.
Yes. Both the web app and desktop app work fully offline. Once loaded, Viztab does not require any internet connection. Your files are processed entirely on your device.
Go past Excel's row limit
Stop truncating your data. Viztab opens the files that Excel cannot — for free, in your browser.
Open Viztab