twineconvert

free · in-browser · no upload

CSV to SQL
Converter

Drop your CSV file. We'll convert it to SQL right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .csv

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a CSV from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your SQL the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert CSV → SQL

What this conversion is actually for

Loading CSV data into a database means either using the database's COPY/IMPORT feature (which differs by engine) or generating portable INSERT statements. The latter works across PostgreSQL, MySQL, SQLite, and SQL Server with no engine-specific syntax. Useful for seed data, test fixtures, and quick imports where you'd rather paste SQL into a query window than configure a CSV importer.

A real example

You have a CSV of 500 product records. You want to seed your dev database with them. Convert to SQL (CREATE TABLE products + 500 INSERT statements), paste into psql / TablePlus / DataGrip, run.

Troubleshooting

The inferred column types are wrong.

We infer types from the first non-null value: integer-looking → INTEGER, decimal-looking → REAL, true/false → BOOLEAN, otherwise TEXT. Override by editing the CREATE TABLE statement before running. For mixed-type columns (some integers, some 'N/A'), edit the type to TEXT to avoid INSERT failures.

INSERT statements fail with 'duplicate key' errors.

Our generated CREATE TABLE doesn't add primary key constraints. If your target database has an existing table with a PRIMARY KEY column, your CSV may contain duplicate values for that column. Either use INSERT OR IGNORE (SQLite) / ON CONFLICT DO NOTHING (Postgres), or drop the table first.

Formats involved

About CSV and SQL

CSV, Comma-Separated Values

CSV is plain text, one row per line, fields separated by commas. The simplest possible tabular data format, which is exactly why it remains the most portable: every spreadsheet, database, programming language, and analytics tool reads CSV. Tradeoffs: no formulas, no formatting, no multiple sheets, and various edge cases around quoting fields that contain commas or newlines.

How to open

Excel, Google Sheets, Apple Numbers, LibreOffice Calc, any text editor, every database import wizard, every programming language with one line of code.

Full CSV format guide →
SQL, SQL dump (CREATE TABLE + INSERT INTO)

A SQL dump file contains the SQL statements needed to recreate a database: CREATE TABLE for schema, INSERT INTO for rows, optionally indexes, constraints, and triggers. The portable subset (single-quoted strings, ANSI types) runs unmodified on Postgres, MySQL, SQLite, and SQL Server. The output of `pg_dump`, `mysqldump`, and SQLite's `.dump` command — the standard backup/seed format for relational databases.

How to open

Any text editor. To execute: `psql < dump.sql`, `mysql < dump.sql`, `sqlite3 db < dump.sql`. Database GUIs (DBeaver, TablePlus, DataGrip, pgAdmin) all import SQL dump files via their migration wizards.

Full SQL format guide →

Related tools

Convert other files to SQL

Convert your CSV to other formats

FAQ

Common questions

Is this CSV → SQL converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert CSV to SQL?

Universal tabular data interchange. Database backups and data seeding. The most common reason to convert is compatibility, SQL works in places where CSV doesn't, or vice versa.

How do I open a CSV file in the first place?

Excel, Google Sheets, Apple Numbers, LibreOffice Calc, any text editor, every database import wizard, every programming language with one line of code.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.