About SuperTools

What this is

SuperTools is a collection of the small utilities developers reach for many times a day — encoding and decoding, hashing, formatting JSON and YAML, comparing text, generating IDs and passwords, reading certificates, doing subnet maths, unlocking PDFs. They are collected in one place with a consistent interface, keyboard shortcuts, and no advertising.

Why it runs in your browser

Most online tools of this kind send whatever you paste to a server. That is a poor trade when the thing you are pasting is an access token, a private key, a customer export, or a password- protected document. Every tool here does its work with JavaScript and WebAssembly running on your own machine, so the payload has no reason to leave it. The privacy page sets out exactly what that promise covers and what it does not.

Who builds it

SuperTools is built and maintained by Amaresh as an open source project. The full source, including every tool implementation and its tests, is public — so the claim that nothing is uploaded is something you can verify rather than take on trust.

Read the source on GitHub. Bug reports and tool suggestions are welcome there.

How it is built

Next.js and React, with every page prerendered as static HTML. Cryptography uses the browser's native Web Crypto API rather than a bundled implementation, and PDF decryption uses a WebAssembly build of qpdf served from this origin. There is no backend API behind any tool.