Excel stops at 1,048,576 rows and freezes on large files. Gridzu has no row limit and opens multi-gigabyte CSVs in seconds — on a normal laptop, works offline.
Two limits collide. First, a hard cap: Excel can't show more than 1,048,576 rows, and it silently truncates anything past that — so you may not even realize data is missing. Second, memory: Excel loads the whole file at once, so a 500MB or 1GB CSV can freeze or crash long before the row cap. "Not responding" is the file being too big, not your computer being slow.
Gridzu doesn't load the entire file into memory. It reads the file's structure and only pulls the rows that are actually on your screen, streaming more as you scroll. That's why a 10-million-row, multi-gigabyte CSV opens almost instantly and scrolls smoothly — there's no row limit and nothing gets truncated.
Opening the file is half the battle — Gridzu also lets you use it. Filter to the rows you care about and export just those (the real answer to "splitting" a giant CSV), remove duplicates, or compare it against another export. See more on the dedicated open large CSV files page.
Your file is opened on your own machine — Gridzu never sends it to our servers. The only thing our service stores is the email you sign in with.
Excel has a hard limit of 1,048,576 rows per sheet. Any CSV with more than that gets silently truncated — the extra rows are dropped. Large files also exhaust Excel's memory and can freeze or crash well before that limit, especially on files over a few hundred megabytes.
Open it in Gridzu instead. Gridzu has no row limit and loads only what's on screen, so a file with tens of millions of rows opens in seconds and scrolls smoothly on an ordinary Windows laptop.
Yes. Gridzu is designed for multi-gigabyte files. It doesn't try to load the whole file into memory at once, so large files that crash Excel open quickly.
No. The file is read entirely on your own computer. Nothing is uploaded.
Gridzu