How to View Large CSV and TSV Files Without Excel

Format you want to check before opening

• Is the character code UTF-8, Shift_JIS, etc.
• Is it separated by a comma, tab, or semicolon?
• Is the first row a header or data?
• Does the value contain newlines, quotes, or delimiters?

Steps to check as a table

1. Select just one file or drop it onto the screen.
2. If characters are garbled or columns are misaligned, change the character code and delimiter.
3. Check the header, total number of rows, total number of columns, and drag column boundaries for better visibility.
4. Use search and page navigation to check not only the beginning but also the middle and end data.

Notes on large files

Even without a fixed file-size limit, the amount you can process depends on available device memory and the browser. Files of several hundred megabytes or more may take time to load and render, and can slow down other tabs.

The viewing tool is suitable for checking values. If you need to aggregate, combine, or update large numbers of rows, use a database or specialized analysis tools.

Do not open CSV files containing personal information on a shared device, and even after viewing, please properly manage the storage location and access privileges of the original file.