How to use the CSV Viewer tool
- Choose a CSV, TSV or Excel file. The row and column counts appear once it has been read.
- Pick the sheet for a workbook, and say whether the first row is a header.
- Click a column heading to sort, and type in the filter box to show only matching rows. Choose a column to filter only that column.
- Page through the results, or export the current view as CSV or Excel.
Worked example: finding one city in 2,500 sales
sales.csv has a header row and 2,500 sales in 4 columns. The note reads 2,500 rows x 4 columns and the table shows the first 100 rows, so there are 25 pages.
- Type Leeds in the filter box and choose the City column. One sale in ten is from Leeds, and the note now reads Showing 1-100 of 250 matching rows.
- Click the Amount heading to sort those 250 rows from smallest to largest; click again for largest first.
- Export as CSV to get sales (filtered).csv with the header and the 250 rows in that order.
How sorting and filtering work
The filter ignores capitals and matches any part of a cell, so lee finds Leeds and Leeds Road. Sorting understands numbers, including numbers stored as text, so 9 comes before 10 instead of after it. Text is sorted the way a person would expect, with numbers inside words compared by value, and empty cells always go to the end. The original row order comes back when you click a heading a third time. None of this changes your file; it only changes the view until you export.
Big files and limits
The file is read once in a background worker and then kept in memory, which is why paging, sorting and filtering are instant afterwards. The practical limit is your device memory: files of a few hundred thousand rows are fine on a laptop, while a phone may struggle with very large ones. Excel workbooks are read sheet by sheet with the values Excel last calculated. Legacy .xls files must be re-saved as .xlsx first.
Your files stay on your device
Your file is opened and displayed entirely in this browser tab. Reading happens in a background worker on your device, and exports are created locally. No row is uploaded, so you can safely inspect exports that contain personal or financial data.
Frequently asked questions
How big a CSV file can I open?
There is no fixed limit. Files with hundreds of thousands of rows usually work on a laptop; the limit is your device memory.
Can I edit cells?
No. This is a viewer for sorting, filtering and exporting. Use a spreadsheet program to edit values.
Does sorting change my file?
No. Sorting and filtering change only the view. Your file is untouched unless you export the view as a new file.
Can I open Excel files too?
Yes. .xlsx files open sheet by sheet; pick the sheet from the menu.
How does the filter match text?
It ignores upper and lower case and finds the text anywhere inside a cell, in all columns or the one you choose.