Developer utilities · local-first
The tools you reach for. Without handing over the payload.
Format, decode, generate, and inspect from one fast workspace. Local tools stay in this browser; network tools show the exact destination before they connect.
Local
Transforms, generators, and decoders execute in your browser.
User-directed network
HTTP and MQTT connect only after you approve the shown destination.
Native advantage
LAN scans and OS-backed secret storage stay in the mobile app.
Most used
Popular developer tools
The tools developers reach for most — all running locally in your browser with zero data upload.
JSON Formatter
Local, available offlineBeautify, minify, and validate JSON with precise errors.
JWT Token Inspector
Local, available offlineInspect headers, claims, and expiry without implying verification.
Regex Tester
Local, available offlineTest expressions with isolated execution, match highlighting, and capture groups.
Password Generator
Local, available offlineGenerate credentials from cryptographically secure browser randomness.
Base64 / URL Encoder & Decoder
Local, available offlineTransform UTF-8 text with Base64, URL, and HTML entity schemes.
Unix Timestamp Converter
Local, available offlineConvert epoch values and ISO dates with explicit units and timezones.
Hash Generator
Local, available offlineCreate MD5, SHA-1, SHA-256, and SHA-512 UTF-8 digests locally.
UUID / ULID Generator
Local, available offlineGenerate secure UUID v4, UUID v7, and ULID batches locally.
Categories
Browse developer tools by category
20 tools
Text & Code
Format, convert, and transform text, JSON, XML, SQL, and identifiers.
5 tools
Crypto & Security
Generate passwords, UUIDs, hashes, and inspect JWT tokens.
3 tools
Files & Templates
Image processing, QR codes, and infrastructure templates.
14 tools
Network & Requests
DNS lookups, IP tools, HTTP testing, and email authentication.
How it works
Three steps. No signup.
01
Pick a tool
Browse the catalogue, search by name or task, or jump from the keyboard shortcut.
02
See the boundary
Every tool states whether it runs locally or reaches the network — before you paste anything.
03
Use it instantly
No account, no install. Local tools work offline after the first visit. Network tools disclose the destination.
Resources
Developer references & guides
Cheat sheets and explainers for common formats, protocols, and patterns.
Mobile workspace
Native tools for the network.
LAN discovery, port scanning, OS-backed secret storage, and platform camera integrations — capabilities that stay in the native mobile app.
FAQ
Frequently asked questions
- What is StackCache?
- StackCache is a free collection of browser-based developer utilities for formatting, decoding, generating, and inspecting data. Every tool states its data boundary — local tools process everything inside your browser, and network tools disclose the exact destination before connecting.
- Is StackCache free to use?
- Yes. Every tool is free with no account, no trial period, and no usage limits. StackCache does not serve ads or sell data.
- Does my data leave the browser?
- Local tools run entirely in your browser — no data is uploaded to any server. Network tools like DNS lookup or HTTP requests connect only to a destination you approve, and the address is disclosed before the request is sent.
- Do I need to create an account?
- No. All tools work without registration, login, or personal information. You can optionally save favorites and snippets using browser-local storage.
- Does StackCache work offline?
- After the first visit, local tools are cached by the service worker and continue to work without an internet connection. Network tools naturally require connectivity for their outbound requests.