DevKit – Developer Tools

Everyday developer tools in a popup. Format, decode, convert and test data without leaving the page. Runs entirely on your device.

DevKit puts 142 everyday developer tools one click away in your toolbar. Format an API response, decode a token or test a regular expression without leaving the page you are on, and without pasting your data into a website. Everything runs locally The tools run inside the extension, on your device. What you paste is never uploaded, logged or sent to a server. DevKit needs no permissions, has no account, no tracking and no ads. Only three tools contact a network service, because that is their whole purpose: What Is My IP, DNS Lookup and the optional MX check of the Email Validator. Built for speed • Search every tool from the header and press Enter to open the best match • Jump to any tool from the keyboard with the command palette (Ctrl/⌘ K) • Smart Paste: paste a value and DevKit recognizes what it is and suggests the right tool • Pin your favorite tools; recently used ones appear on the home screen • The popup reopens on the last tool you used, with your input kept • Open DevKit in a full tab when you need more room • Light and dark themes, and a code editor with syntax highlighting • Press Alt+Shift+D to open DevKit What's inside The tools are organized into eleven groups: • Time and dates: convert Unix timestamps, build and explain cron expressions, and work across time zones. • Encoding: encode and decode Base64 and URL strings, and inspect JWTs and X.509 certificates. • Hashing and security: generate hashes, secure passwords, unique IDs and RSA key pairs. • Formatting: beautify or minify code and markup in the most common languages. • Validation: check config files and data against their syntax, including CI pipeline files. • Data conversion: turn structured data from one format into another, or generate typed models from a JSON sample. • Numbers: convert between number bases, data sizes and units. • Text: compare two texts, test regular expressions, change case and clean up lists. • Web: preview HTML/CSS/JS, generate server configs, meta tags and QR codes, and look up HTTP status codes. • CSS: convert colors, build gradients, shadows and layouts, and check contrast for accessibility. • Network: calculate subnets, look up DNS records and check your public IP. Every tool is also available on the web at https://devkitutils.com, with a guide and FAQ for each tool.