Open Large CSV Files Online: how it works
How it works
- Open a UTF-8 CSV, TSV or TXT file with the button above, or drop it into the workbench. The web version accepts files up to 32 MiB; the size check runs before anything is uploaded.
- Move through the file: type a row number in the name box to jump straight to it, or filter and sort columns to narrow the view. Even a million rows stay scrollable.
- Read what you need, then close the file or continue to Doctor and repairs. Viewing alone never changes the file; saving is a separate, deliberate action.
What stays exactly the same
Opening, jumping, filtering and sorting change only the view. The saved row order and every byte of the file stay as they are until you choose an edit or a repair.
Fields stay text: leading zeros and long numbers are not converted. If you make no edits, Preserve output keeps the original bytes exactly.
Limits
Files are uploaded to the cellsmith.app server and held in memory, not kept only in your browser. The web version accepts UTF-8 text files up to 32 MiB each. Files expire 30 minutes after the last activity; opening another file or restarting the server also clears the current document and unsaved work.
Questions about this tool
Is there a maximum number of rows in a CSV?
No. The CSV format itself has no row limit; one Excel sheet holds 1,048,576 rows, which is why large exports often fail to open in Excel. This workbench opens CSVs with more rows than one Excel sheet holds. A file made of millions of very short rows can reach the web version's row capacity before it reaches the size limit; the planned desktop app will handle files like that right on your computer.
What is the largest file the web version opens?
Up to 32 MiB per file, uploaded to the cellsmith.app server, held in memory and deleted after the retention period. Larger files are declined before upload; the planned desktop app will handle files right on your computer.
Will opening a large file change it?
No. Opening, jumping to rows, filtering and sorting only change the view. Nothing in the file changes until you choose an edit or repair and then save.