CSV Viewer

What is the CSV Viewer?

The CSV Viewer is a tool that allows you to view the contents of CSV (Comma-Separated Values) and TSV (Tab-Separated Values) files directly in your browser without having to launch a spreadsheet program.CSV files are used for a wide range of purposes, including data exchange between systems, product data for e-commerce sites, customer lists, web analytics, and exports from various administrative interfaces.However, when opened directly in a text editor, it can be difficult to distinguish column delimiters in CSV files, and data with long lines or quotation marks can be hard to follow. This tool automatically parses CSV and TSV files into rows and columns and displays them in an easy-to-read tabular format.

Files can be imported via drag-and-drop, file selection, or direct text paste. You can choose a delimiter from comma, tab, semicolon, or pipe, and automatic detection is also available.Since semicolon-separated files are common in overseas systems, Shift_JIS is often used in older Japanese business systems, and UTF-8 or TSV are sometimes used for development purposes, you can adjust the settings to match the data source. You can also choose whether to treat the first row as a header.

You can filter the loaded data using keyword search. Since the search covers the entire table, you can quickly find the values you want to check, such as product names, email addresses, IDs, and statuses.Additionally, clicking a column header sorts the data in ascending or descending order. Since rendering a large number of rows at once can slow down the browser, the display is divided into pages, and users can adjust the number of rows per page. The design allows users to quickly navigate to the necessary sections while reviewing the entire CSV.

This CSV Viewer does not upload selected files or pasted CSV data to the server. Parsing and table display are performed within the browser you are using via JavaScript. Therefore, it is easier to handle even sensitive data compared to methods that send files to external services.However, please take separate precautions regarding device-side security, such as when using shared devices or browser extensions. In the future, by combining this tool with other tools—such as those for converting to and from JSON—you’ll be able to perform everything from data verification to conversion entirely within the browser.

Key Features

• You can view CSV and TSV files in tabular format.
• Supports drag-and-drop, file selection, and direct pasting.
• You can choose between comma, tab, semicolon, or pipe delimiters.
• You can choose from UTF-8, Shift_JIS/CP932, and Windows-1252.
• You can search for keywords across the entire table.
• Click a column header to sort in ascending or descending order.
• Pagination makes it easier to view even large CSV files.
• File contents are processed within the browser and are not sent to the server.

How to Use the CSV Viewer

1. Drag and drop a CSV or TSV file, or open one by clicking "Select File." You can also paste text directly.
2. If you encounter garbled text or misaligned columns, change the character encoding or delimiter, then click “Apply Settings and Reload.”
3. If the first row is the item name, turn on "Treat the first row as a header."
4. You can filter the entire table by keyword using the search bar at the top of the preview.
5. Clicking a column header sorts the data in ascending or descending order based on that column.
6. Adjust the number of rows per page as needed, and navigate to the previous and next pages to verify.

Precautions for Use

• Since large CSV files consume a significant amount of device memory, this tool has a 50MB size limit.
• Depending on the CSV specifications or the source of the data, custom escaping or line break formats may be used.
• Since Shift_JIS detection is not fully automatic, please manually select the character encoding if characters appear garbled.
• Since Excel-specific formulas, cell formatting, and multiple sheets are not included in CSV files, this tool does not handle them.

Frequently Asked Questions About the CSV Viewer

What is a CSV?

CSV is a text format that stores multiple items, primarily separated by commas. It is widely used for exchanging tabular data.

Can TSV files be displayed as well?

Yes. You can view this data by having the system automatically detect tab-delimited files or by selecting "Tab-separated (TSV)" as the delimiter.

Will the CSV file be uploaded to the server?

No. Files are loaded, parsed, searched, and sorted within the browser you are currently using.

Can you open CSV files in Shift_JIS?

Yes. You can select "Shift_JIS / CP932" as the character encoding and reload the page.

What should I do if the text appears garbled?

Please switch the character encoding to UTF-8 or Shift_JIS / CP932 and reload the page. The actual character encoding of the file must match the setting.

Does it support CSV files separated by semicolons?

Yes. It supports comma, tab, semicolon, and pipe delimiters.

Can it handle cells that contain commas or line breaks?

As long as the CSV is properly enclosed in double quotes, it can parse commas and line breaks within cells.

Can I sort the columns?

Click a column header to sort in ascending order; click it again to sort in descending order.

Can I search within the CSV file?

Yes. When you enter text in the search field, only rows that match that text across all columns will be displayed.

Can you display CSV files where the first row is not a header?

Yes. If you turn off “Treat first row as a header,” it will display placeholder headings such as “Column 1” and “Column 2.”

Can you open Excel files (.xlsx)?

This tool is for CSV and TSV files only. Please save or export .xlsx files to CSV before using them.

Does it support large CSV files?

Although pagination helps reduce rendering load, we recommend and limit file sizes to 50 MB or less to conserve browser memory.