Frequently Asked
Are these tools free?
Yes. Every Single Page Sandbox tool is completely free — no paywall, no premium tier, no in-app purchase. The download is gated only by a free Substack newsletter subscription.
Do they need an account or signup?
No. None of the tools require an account, login, or sign-in to use. The Substack subscription is for the newsletter, not for the tools themselves — you can also click "Already a subscriber" and proceed.
Does my data upload anywhere?
No. Every tool processes your text, images, and CSV files entirely inside the browser. Nothing is uploaded to a server. The site uses cookieless analytics for anonymous pageview counts only — no content of what you type or generate is ever transmitted.
Can I use them offline?
Yes. Each tool is a single HTML file. After you download the zip, extract home.html and open it directly in your browser — works fully offline with no internet connection.
Who builds and maintains these?
Nirav Bhatt at Brain Bound Learning. New tools and how-they-work deep-dives are posted on the Substack publication.