JOIN Builder Online - Free Browser Tool

Join type

Tables

Join keys

Matching

Left table CSVCSV4rows·4left

Right table CSVCSV4rows·4right

join type: LEFT
left rows: 4
right rows: 4
matched left: 2
left only: 2
right only: 1
output rows: 5

Generated join SQLSQL

SELECT
  l.*,
  r.*
FROM users l
LEFT JOIN orders r
  ON l.user_id = r.user_id;

Tip: use samples, upload, copy, download, and send-to actions inside the workspace where available.

What is JOIN Builder?

JOIN Builder is a free, browser-based tool that helps you produce ready-to-use output in seconds. Build INNER/LEFT/RIGHT/FULL joins visually with key picker. 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.

How to use JOIN Builder

1Configure the options to describe what you need.
2The output is generated instantly and updates as you tweak settings.
3Copy the generated result or download it.

Features

Live output that updates with every option
Copy or download the generated result
100% client-side — no upload, fully private
Free with no account, no watermark, and no daily limit
Works on large inputs, limited only by your device's memory
Load a sample, then copy, download, or share your result

Common uses

Drafting and checking queries without a database connection
Quick one-off generator jobs without opening a heavy app
Preparing data before importing it elsewhere
Sharing a reproducible result with a teammate via a link

Frequently asked questions

How do I use JOIN Builder?: Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Build INNER/LEFT/RIGHT/FULL joins visually with key picker.
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 JOIN Builder 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.

What is JOIN Builder?

Frequently asked questions

How do I use JOIN Builder?

Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Build INNER/LEFT/RIGHT/FULL joins visually with key picker.

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 JOIN Builder 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.