Privacy-first development
Developer tools that never see your data.
Most online developer tools upload your input to a remote server for processing. StackCache takes a different approach: every tool runs locally in your browser. Your JSON, JWT tokens, passwords, images, and code never leave your device.
What "local-first" means technically
Local-first means the tool's processing logic — parsing, formatting, hashing, encoding, image manipulation — executes entirely in your browser's JavaScript engine or a dedicated Web Worker. The input bytes never enter an HTTP request body, are never buffered in a server's memory, and are never written to a remote log or database.
When you format JSON, decode a JWT, generate a UUID, or resize an image on StackCache, the computation happens on your CPU using your browser's built-in APIs like SubtleCrypto, TextEncoder, and CanvasRenderingContext2D. The result stays in tab memory and is cleared when you navigate away.
StackCache has no account system, no analytics scripts, no advertising trackers, and no tool-processing backend. The hosting provider delivers static HTML, CSS, and JavaScript files — after that first load, local tools work without any further network access.
Tools that work completely offline
These 32 tools process everything locally. After the app shell is cached, they work without any internet connection.
Network tools with disclosed destinations
Some tools need a network connection — DNS lookups query Cloudflare's public resolver, public IP checks contact ipify, and RDAP lookups reach the authoritative registry. In every case, the exact destination is shown before you submit, no proxy sits between your browser and the service, and the result stays in local memory.
How StackCache compares
| Feature | StackCache | Typical online tools |
|---|---|---|
| Data processing | In your browser | On the provider's server |
| Account required | No | Often yes |
| Analytics / tracking | None | Google Analytics, ads |
| Works offline | Yes (local tools) | No |
| Network disclosure | Destination shown first | Not stated |
| Third-party scripts | Zero | Multiple |
Frequently asked questions
- Is StackCache really free?
- Yes. Every tool is free with no usage limits, no account, and no premium tier. The tools run in your browser, so there are no server costs to recover per request.
- Can I use StackCache on a corporate network?
- Yes. Because local tools make no outbound requests after the page loads, they work behind strict firewalls and VPNs. Network tools only contact their disclosed destination.
- Is there a desktop or mobile app?
- The web app works as a PWA that can be installed from your browser. A native mobile app is available for iOS and Android with additional features like port scanning and OS-level secret storage.
- How do I know the tools actually run locally?
- Open your browser's Network tab in developer tools before using any local tool. You will see zero requests to StackCache or any other server during processing. The privacy boundary is stated on every tool page.
- What about sensitive data like JWT tokens or passwords?
- JWT decoding, password generation, and hash computation all run locally. Tokens and passwords stay in tab memory and are cleared when you leave the page. They are never sent to any server.
Start using privacy-first tools
No signup, no install, no data collection. Open the tools and start working.