How It Works
No uploads, no account, no tracking of your tool data. Everything runs right in your browser—here's what that actually means for you.
How It Works
Data Flow
Local Execution
When you enter data into any of our tools, it is read directly into your browser's memory. All processing happens using the Web Crypto API (for cryptographic operations) or native JavaScript. The results are displayed in your browser window. At no point does your data leave your device or travel over the network.
What Leaves Your Browser
After the initial page load, nothing you type, paste, or upload is ever sent anywhere. The code is completely static. You can verify this yourself: open your browser's Developer Tools (F12), switch to the Network tab, and use any tool. In that list you will see our own files—on first use the regex tester fetches its engine and the image compressor fetches the code it compresses with—and Cloudflare's cookie-less page-view ping, which the CDN injects on every page load. What you will not see is a request carrying your input.
No Persistent State
We do not use cookies or IndexedDB, and we never store your tool data. Three kinds of browser storage are in play, and none of them holds your inputs, files, keys, or results: two local preferences (your theme choice under the "theme" key, and the dismissed install banner under the "zeyrovault-pwa-install-dismissed" key — written only when you use the theme switch or dismiss the banner), a session-scoped sessionStorage entry listing the tools you opened most recently (names only, cleared when you close the tab), and the service worker's offline cache of the app's own files and the pages you visited. Everything you paste, encrypt, hash, or compress stays in memory and is released when you leave the page. Nothing about it is stored or sent anywhere.
Technical Implementation
Our tools are built as static HTML, CSS, and JavaScript files. The cryptographic operations use the browser's native Web Crypto API, which is implemented in highly optimized C++ code within the browser engine. This provides both security (the algorithms come from the browser itself) and performance (native code execution). The one exception is MD5, which the Web Crypto API does not offer and which therefore uses a small bundled JavaScript implementation.
Verify It Yourself
You do not need to trust our claims. You can verify everything:
- 1Open Developer Tools (F12) and check the Network tab—you will see our own files and Cloudflare's cookie-less page-view ping, but no request carrying your input
- 2Verify our claims in DevTools
- 3Reload a visited page with the network disabled and watch it replay from the offline cache
- 4Use a packet sniffer to confirm that nothing you type or paste is transmitted
- 5Inspect the code in DevTools Sources panel
- 6Verify the page is served over HTTPS with a valid certificate
- 7Check browser memory usage to confirm no data leaks
Why This Matters
Traditional online tools send your data to their servers for processing. Even if they claim to delete it immediately, you have no way to verify this. With our client-side approach, your data never leaves your device, giving you complete control and privacy. This is especially important for sensitive data like passwords, private keys, and personal information.
Zero-Knowledge
- Your data
- How you use it
- Your patterns
- Access your data
- Share with third parties
- Lose in breach
- Your data content
- Your passwords
- How you use it
- Access your data
- Share what they lack
- Lose what they don't have