Rename Columns

What is Rename Columns?

Rename Columns is a free, browser-based tool that helps you get the job done quickly. Bulk-rename CSV/JSON columns. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.

Used by

• Data engineers
• Analytics engineers
• Database administrators
• Operations teams

Recommended workflow

1. 1

   Prepare the input

   Use this tool as the focused step in a larger browser-based workflow.

2. 2

   Run Rename Columns

   Review the preview, copy or download the result, and keep everything local in your browser.

3. 3

   Next recommended tool

   Normalize Column Names: snake_case, camelCase, or kebab-case headers.

   Open tool
4. 4

   Then continue with

   JSON Key Renamer: Rename keys with rules (snake_case, prefix strip, mapping table).

   Open tool
5. 5

   Then continue with

   CSV Filter Builder: Build complex row filters across columns visually.

   Open tool

Frequently asked questions

How do I use Rename Columns?

Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Bulk-rename CSV/JSON columns.

Is my data uploaded or stored anywhere?

No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.

Is Rename Columns free?

Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.

What's the maximum file size?

There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.

Do I need to install anything?

No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.