CSV & Excel Viewer

about this tool

Opening a spreadsheet without a spreadsheet

Drop in a CSV, TSV, or an Excel or OpenDocument file — .csv, .tsv, .txt, .xlsx, .xls, .xlsm, .ods — and read it as a table you can sort and search. Workbooks with several sheets let you switch between them.

The point is to answer a question about a file without opening a spreadsheet application, waiting for it, and being asked whether you want to save changes on the way out.

To turn the table into JSON for a program, or go the other way, use the CSV to JSON converter.

Delimiters

Comma, semicolon, tab and pipe are all handled. Semicolon files are common from European locales, where the comma is the decimal separator and Excel writes semicolons instead — which is why a valid CSV sometimes arrives as a single column of text.

What a spreadsheet does to your data that this does not

This is the real reason to look at a CSV in a viewer before importing it. Excel and Google Sheets apply type conversions on open, and they are lossy:

• Leading zeros vanish. A postcode 01234 or a product code 007 becomes 1234 and 7.
• Long numbers become scientific notation, so a 16-digit credit card or a large ID renders as 1.23457E+15, and the original digits are gone if you save.
• Anything resembling a date is converted. The gene name SEPT2 famously became a date so often that geneticists renamed the genes rather than keep fighting Excel.
• Regional date order flips. 03/04/2024 is March in the US and April in the UK, and nothing in the file records which was meant.

Here the cells are shown as they exist in the file. If a value looks wrong in your spreadsheet but right here, the spreadsheet changed it.

Spreadsheet formats

Reading .xlsx, .xls, .xlsm and .ods needs a full spreadsheet parser, which is fetched the first time you open one of those rather than on every page load — which is why this tool is badged as loading a library. Plain CSV and TSV files need none of it and parse immediately.

Nothing is uploaded

A spreadsheet is usually the most sensitive file an organisation emails around: customer lists, salaries, orders, patient records. This one is read by your browser directly from disk — it never goes to a server, which is exactly what you should require of anything you open a payroll file in.

For two exports of the same table rather than one file, CSV diff matches the rows on a key column and reports which cells changed.

To load a CSV into a database rather than read it, CSV to SQL works out each column's type and writes the CREATE TABLE and INSERT statements for PostgreSQL, MySQL, SQLite or SQL Server.

questions

Which file types can it open?

CSV, TSV and plain text delimited files, plus Excel and OpenDocument workbooks — .xlsx, .xls, .xlsm and .ods. Workbooks with several sheets let you switch between them.

Why do leading zeros disappear when I open a CSV in Excel?

Because Excel converts anything that looks numeric on open, so a postcode 01234 becomes 1234. Long numbers also become scientific notation and date-like values get converted. Viewing the file here shows the cells as they actually exist.

Is my spreadsheet uploaded?

No. The file is read by your browser directly from disk and never sent to a server, which is what you should require of anything you open a payroll, customer or patient file in.

Why does my CSV show as a single column?

The delimiter does not match. Files from European locales are often semicolon-separated, because the comma is the decimal separator there and Excel writes semicolons. Switch the delimiter and the columns appear.

Can I sort and search the data?

Yes, columns can be sorted and the table searched, which is usually enough to answer a question about a file without opening a spreadsheet application at all.