Frequently Asked Questions

ToolsStack is a free collection of 21 online developer tools that run entirely in your browser. All processing happens client-side — no data is ever uploaded to any server, ensuring your data stays private and secure. Tools include JSON formatter, Base64 encoder/decoder, JWT decoder, hash generator, diff checker, regex tester, QR code generator, and more across four categories: Developer Tools, Generators, Text Tools, and Image & Color.

Yes, all tools are completely free with no usage limits. There are no paid tiers, no sign-up requirements, and no premium features. Because every tool runs client-side in your browser, we have no server processing costs to offset — which means we can keep everything free, permanently.

Yes. All tools process data entirely in your browser using JavaScript. No data is ever uploaded, stored, or transmitted to any external server. You can verify this by opening your browser's Developer Tools (F12) and checking the Network tab while using any tool — you will see zero outbound data requests. After the initial page load, every tool works offline.

No installation, no sign-up, and no browser extensions required. All tools work directly in your web browser. Just visit toolsstack.org, pick a tool, and start using it immediately.

ToolsStack offers 21 tools across four categories. Developer Tools (11): JSON Formatter, JSON to CSV, Base64 Encode/Decode, URL Encoder/Decoder, HTML Entity Converter, JWT Decoder, SQL Formatter, Regex Tester, Hash Generator (MD5/SHA-1/SHA-256/SHA-512), PDF Compressor, PDF to JPG. Generators (3): UUID Generator, Password Generator, Lorem Ipsum Generator. Text Tools (4): Word Counter, Case Converter, Diff Checker, Markdown Preview. Image & Color (3): Color Picker, QR Code Generator, GIF Maker.

When you load a ToolsStack page, the HTML, CSS, and JavaScript files are downloaded to your browser. After that, all tool functionality — formatting, encoding, hashing, generating, comparing — runs locally on your device using JavaScript executed by your browser. No data is sent back to any server for processing. This approach is both faster (no network round-trip) and more private (your data stays on your device).

Yes. After a tool page has fully loaded in your browser, you can disconnect from the internet and continue using it. All processing is done locally. The only requirement is the initial page load to download the tool's code — after that, no internet connection is needed.

ToolsStack works on all modern browsers: Chrome, Firefox, Safari, Edge, and Brave. JavaScript must be enabled since all tools run client-side. Mobile browsers are also supported for most tools, and the site is fully responsive for small screens.

The Hash Generator supports MD5, SHA-1, SHA-256, and SHA-512. For security-sensitive purposes, SHA-256 or SHA-512 are recommended. MD5 and SHA-1 are considered cryptographically broken for security use but remain useful for checksums, file integrity verification, and non-security applications.

No. Passwords are generated using cryptographically secure randomness (crypto.getRandomValues) entirely in your browser. Generated passwords are never stored, logged, or transmitted to any server. They exist only in your browser's memory and are lost when you leave the page — unless you copy and save them yourself.

A JWT (JSON Web Token) is a compact, URL-safe way to transmit claims between parties, commonly used for authentication in web applications. It consists of three parts: a header, a payload, and a signature. The JWT Decoder decodes and displays the header and payload — these parts are base64-encoded, not encrypted, so anyone with the token can read them. The decoder does not verify signatures; signature verification should be done on your own server with your secret key.

Yes. We welcome feedback from the developer community. If you have a suggestion for a new tool, a feature request for an existing one, or a bug report, please email [email protected].