I didn't have a PC for my database class, so I built my own T-SQL Sandbox in the browser

Hey everyone.

I'm a systems engineering student, and recently I ran into a major issue: I was left without a computer right in the middle of the semester. I desperately needed to practice for my database assignments and thought I could easily find an online sandbox to get by.

I was wrong. Most web-based SQL editors don't support Transact-SQL properly, or they lock essential features behind a paywall before you can even do the basics.

I survived those weeks however I could, but that frustration stuck with me. As soon as I finally got my PC back, we decided to solve this exact problem at our 2-person startup (Zone 0). Today, we are releasing the first version of T-SQL Online (https://tsqlsandbox.online).

It's a web environment to practice T-SQL directly in your browser. No local SQL Server installations, no weird server configurations, and no licenses. It is exactly the tool I wish I had when my computer broke down.

What you can do in this v1:

Create and alter tables with all constraints (Primary/Foreign keys, Unique, Check, Default).

Full CRUD operations and all types of JOINs.

Basic logic: variables, IF/ELSE, WHILE, and TRY/CATCH.

Automatic ER Diagram generation as you build your schema.

Export your SQL scripts when you're done.

Transparency (Tech & Financial):
We are fully bootstrapped with zero funding, so server costs come straight out of our pockets. Right now, it's free to use (1-hour sessions and 1 temporary database per user). To keep it sustainable long-term, we are in the process of integrating ads. We are also planning premium tiers for those who need longer sessions, multiple databases, and saved query history.

Also, technically speaking, the engine simulates T-SQL behavior (there is no real SQL Server running behind it), so it doesn't support complex stored procedures just yet.

I need your raw feedback.
I'd love for you to test it out and try to break it. There's a message icon inside the app to drop your feedback, bug reports, or suggestions. Or you can just leave your thoughts in the comments here!