CSV TOOLS

Eighteen quick tools for the CSV jobs that come up every week: open a file too big for a spreadsheet, remove duplicate rows, fix broken quotes, trim stray spaces, or turn the table into JSON or SQL. Drop your file, pick a tool, and export the result. Your file stays in this browser tab and is never uploaded.

Loading the CSV tools.

About 2csv

How Can You Verify That Your Files Never Leave This Browser?

You do not have to take our word for it. Browser developer tools list every request a page makes, so you can watch 2csv work and confirm that your data is never sent anywhere. The check takes about a minute.

Open your browser developer tools with F12, or Cmd+Option+I on a Mac, and select the Network tab.
Reload the page and let it finish. You will see the page's own files (including the background file parser), its web fonts, and one anonymous page-view request. No file has been chosen yet, so none of them can contain your data.
Click the clear icon in the Network tab so that the log is empty.
Open a CSV file, run any tool on it, and download the result.
Look at the Network tab again. It is still empty. Reading, changing, and saving the file made no request at all. For extra proof, turn on offline mode after the page loads: every tool keeps working.

Your file is read into this tab's memory with the browser's own file reader, parsed and changed by code that is already on the page, and handed back to you as a download. It is never uploaded, never stored in the browser, and gone when you close the tab. The only other request the site can make is the feedback form, and only when you submit it.

The production site also sends a Content-Security-Policy header that tells your browser to refuse connections to anywhere except this site and the anonymous analytics endpoint, so even a bug could not send your data elsewhere.

What Is 2csv?

2csv is a set of eighteen quick CSV tools that run entirely in your web browser. A CSV file is a plain text table where each line is a row and commas (or semicolons, tabs, or pipes) separate the columns. 2csv opens that table in a fast grid and gives you one focused tool for each common job.

The tools cover viewing and profiling, sorting, filtering, validating, removing duplicates, trimming whitespace, find and replace, removing rows, editing cells, splitting and merging columns, converting column types, and converting to and from JSON, SQL, and TSV. There is no account, no install, no subscription, and no usage limit. Every tool costs $0.

Why Does It Matter Where a CSV Is Opened?

CSV files are how customer lists, payroll exports, order histories, patient rosters, and CRM dumps move between systems. They often hold names, email addresses, phone numbers, and account details for thousands of people. Most online CSV tools upload that file to a server, process it there, and send a result back, leaving a copy under someone else's retention policy.

2csv does the work inside your browser tab instead. The file is read into the tab's memory, changed by code already on the page, and handed back to you as a download or a copy. Nothing is uploaded or stored, and the data is gone when you close the tab. You can confirm this yourself with the developer tools check on this page.

Which CSV Tools Are Included?

CSV viewer: open a CSV of any size, scroll every row, and see a profile of each column.
Sort CSV: sort rows by up to five columns, as text, numbers, or dates.
Filter CSV: show only rows that match an expression such as price > 10 AND state = "NY".
CSV validator: find ragged rows, broken quotes, bad headers, encoding problems, and values of the wrong type.
Remove duplicates: find and remove duplicate rows, comparing whole rows or chosen columns.
Trim whitespace: trim spaces, collapse double spaces, and remove invisible characters and empty rows.
Find and replace: replace text in one column or all, with match case, whole cell, and regular expressions.
Remove rows: delete rows by number or range, first or last rows, empty rows, or rows matching a rule.
CSV editor: edit cells, add or delete rows, and add, rename, move, or delete columns.
Split column: split one column into several at a delimiter, such as a full name into first and last.
Merge columns: join two or more columns into one with a separator you choose.
Column type converter: turn a column into clean numbers, ISO dates, true/false, or a chosen letter case.
CSV to JSON: export an array of objects, an array of arrays, or JSON Lines.
JSON to CSV: flatten a JSON array or JSON Lines into a table with dotted column names.
CSV to SQL: write INSERT statements and an optional CREATE TABLE for four database dialects.
CSV to TSV: write tab-separated values that paste cleanly into a spreadsheet.
TSV to CSV: turn a tab-separated file into a standard, properly quoted CSV.
CSV splitter: cut a large CSV into smaller files with the header repeated in each.

How Do You Use 2csv?

Drop a file on the page, click to choose one, paste text, or press Try a sample file to load a small set of USD order data.
Check the detected delimiter, encoding, and the First row is the header toggle. Each can be changed if the guess is wrong.
Pick a tool. The tool buttons switch tools in place and keep your data, so you can run one job after another.
Download or copy the result from the export bar under the grid, as CSV, TSV, JSON, JSONL, or SQL.

Undo keeps your last five changes, and Reset to original returns the table to the file exactly as it was first read. If you try to leave the page with unsaved changes, the browser asks before closing it, so a stray click does not throw away your work.

How Does 2csv Handle Messy or Broken CSV Files?

The parser follows RFC 4180, the common definition of the CSV format, but it repairs problems instead of refusing the file. Real exports are often slightly broken: a quote that never closes, a row with an extra comma, a byte-order mark at the start. Every repair is recorded with its file line number and shown in the validator.

Rows with too few fields are padded with empty cells.
Rows with too many fields widen the table with extra columns, so no value is lost.
A quote that never closes is read as a literal character instead of swallowing the rest of the file.
Blank lines are skipped and counted, and a byte-order mark is removed.
A file that is not valid UTF-8 is read as Windows-1252, and the page tells you so.

How Large a CSV File Can 2csv Open?

A file of about 100 MB, or around a million rows, runs smoothly on a typical laptop. Files up to about 200 MB open with a warning that things may be slower. Files over about 500 MB cannot be opened, because the whole table has to fit in the memory the browser gives one tab.

Parsing runs in a background Web Worker, so the page stays responsive while a large file loads. The grid is virtualized: it only draws the rows on screen, which is why scrolling a million rows feels the same as scrolling fifty. A phone with little memory will reach its limit sooner than a laptop.

What Formats Can You Export?

Every tool page has the same export bar under the grid. It can download a file or copy the text to your clipboard, and it shows a live preview of the real first rows before you commit. If a filter is active, the export contains only the matching rows, and the bar says so.

CSV with a comma, semicolon, pipe, or tab delimiter, and CRLF or LF line endings.
TSV, JSON, JSON Lines, and SQL INSERT statements.
An optional byte-order mark so Excel reads UTF-8 accents correctly.
Optional formula protection, which puts an apostrophe before cells that start with = + - or @ so spreadsheets do not run them.
Quote every field, and include or leave out the header row.

What Can 2csv Not Do?

Being clear about the edges saves you time. 2csv is a set of quick tools for one table at a time, not a database or a spreadsheet application, and some jobs that people ask about are deliberately not in this version.

It does not join two CSV files on a key column, and it does not build pivot tables or group-by summaries.
It does not run SQL queries. The filter uses a small expression language instead, and CSV to SQL only writes statements.
It does not read or write Excel .xlsx files. Save as CSV from Excel, or paste copied cells.
It does not do fuzzy matching for near-duplicate rows, and it does not draw charts.

If one of those is what you need, a database or a full spreadsheet application is the better tool. 2csv is deliberately the quick one, built for the cleanup and conversion jobs that come before or after that bigger work.

Who Is 2csv For?

Analysts and operations staff who receive exports too large or too messy for a spreadsheet to open cleanly.
Developers who need JSON, JSON Lines, or SQL INSERT statements from a CSV without writing a one-off script.
Anyone handling customer, employee, or financial records who would rather not upload them to a stranger's server.
People on locked-down work laptops who cannot install a desktop data tool.

2csv is part of the 2suite.io privacy-first ecosystem. To stack several CSV or JSON files into one, use 2join. For file formats other than CSV, 2convert handles the conversion, and 2pdf covers PDF jobs, all in the same browser-only way.

Frequently Asked Questions

Does 2csv cost anything?

No. Every tool costs $0, with no account, no usage limits, no paid tier, and nothing to install.

Are my files uploaded to a server?

No. Every tool runs in your browser tab. Your file is read into the tab's memory, processed there, never stored, and gone when you close the tab.

Does 2csv collect any analytics?

The only analytics is one anonymous page-view count, sent when a page loads, before you can choose a file. If you submit the feedback form, your vote and comment are sent too. Nothing about your files is ever included.

Can 2csv open Excel files?

Not .xlsx files in this version. Save the sheet as CSV from Excel, or copy the cells and paste them onto the page; copied cells arrive tab-separated and open as a table.

How big a file can I open?

About 100 MB or a million rows runs smoothly on a typical laptop, up to about 200 MB works with a warning, and files over about 500 MB cannot be opened.

Which delimiters and encodings are supported?

Comma, semicolon, tab, and pipe are detected automatically. UTF-8 is detected, byte-order marks are handled, and files that are not valid UTF-8 are read as Windows-1252. You can override either choice.

Can I use several tools on one file?

Yes. The tool buttons switch tools in place and keep the data, so you can remove duplicates, trim whitespace, and then export without reloading. Undo keeps the last five changes.

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