About DevDesignKit

Fast, private, in-browser tools for people who build for the web.

DevDesignKit is a focused collection of utilities for developers and designers who want to get small jobs done quickly: formatting JSON, testing a regex, checking color contrast, converting an image, without signing up for an account or handing their work to a third-party server.

Every tool runs entirely in your browser. Nothing you paste, type, or import is uploaded, stored, or seen by anyone else. When you close the tab, your data is gone with it.

Every utility on this page is a thin layer over public web standards that the browser already implements. The JSON formatter parses and reserializes text against the grammar defined in RFC 8259. The Base64 tool follows the encoding alphabet and padding rules from RFC 4648. The contrast checker computes the same ratio WCAG 2.2 uses to judge text legibility. Gradients and shadows are emitted as plain CSS property values, and the SVG and WebP converters work through the browser's native image APIs. Because the work runs where the browser runs, neither the source document nor the result ever travels over the network.

Client-side processing has a real cost. Heavy inputs draw on the device's own CPU and memory.

Who it's for

  • Independent developers who need quick, reliable utilities without opening a heavier IDE plugin or an account-gated SaaS.
  • Designers who want instant feedback on contrast, gradients, and shadows while they build interfaces.
  • Students and tinkerers who want a reference for CSS layout, HTTP status codes, and HTML semantics in one place.

Our operating principles

  • 100% client-side. All processing happens in browser memory and on the page itself.
  • Zero uploads, zero tracking. No accounts, no forms, and no analytics that follow you around.
  • Lightweight by default. Self-hosted fonts and a static build keep pages fast. The current build loads no third-party resources at runtime; advertising will remain paused until its consent controls are configured.

What's inside

DevDesignKit currently ships 9 tools across three categories, plus 3 cheat sheets and 3 snippet collections: all free, all client-side.

The three categories sit on three different parts of the platform. Code tools implement data formats: JSON follows RFC 8259, Base64 follows RFC 4648, and the regex tester evaluates patterns the way ECMAScript defines them. Design tools produce CSS that the rendering engine consumes, so their results follow the W3C CSS specifications, and the contrast checker reports against WCAG 2.2 success criteria.

The cheat sheets and snippets condense the same sources into quick references.

Code Tools

  • JSON Formatter & Validator
  • Base64 Encoder / Decoder
  • Regex Tester & Debugger

Design Tools

  • WCAG Color Contrast Checker
  • CSS Gradient Generator
  • CSS Box Shadow Generator

Media Tools

  • SVG to PNG/ICO Converter
  • WebP Image Converter
  • Client-Side Image Compressor

Cheat Sheets

  • CSS Layout Guide
  • HTTP Status Codes
  • HTML5 Semantic Tags

Snippets

  • Pure CSS Hover Effects
  • Tailwind Button Presets
  • Micro-animations

Built with

DevDesignKit is built with React, TypeScript, and Vite, and is served as a purely static site. There is no backend, no database, and no server-side code to maintain. Fonts are self-hosted (Geist Variable), and the current build loads no third-party resources at runtime and keeps advertising paused until its consent controls are configured: which is as much a performance decision as a privacy one. The whole project compiles to static assets that can be hosted anywhere.

The build pipeline is deliberately unremarkable. React and TypeScript source code is compiled by Vite into plain HTML, CSS, and JavaScript at build time, and the result is a folder of static assets that any static host, shared server, or CDN edge can serve. Because the deployed site has no application server behind it, there is no database to migrate, no authentication layer to secure, and no runtime endpoint that could receive a file. That is what makes the privacy promise structural rather than aspirational. This keeps maintenance near zero.

The same choice has a visible flip side: no backend also means no server-side logs, no user accounts, and nothing to monitor overnight.

Site operator

DevDesignKit is created and operated by Peter, an individual developer based in the United States. Peter is responsible for the content published here. The site is maintained as a personal project, and its tools, cheat sheets, and snippets are reviewed and updated as the underlying web platform evolves. For corrections, questions, or to report an issue, use the contact details below.

Reviewed as the platform evolves has a concrete meaning here. When W3C updates an accessibility standard, when IANA registers a new HTTP status code, or when the WHATWG specification changes the meaning of a semantic element, the matching tool or cheat sheet has to be checked against the new text. Corrections then land as ordinary page updates, so what you see is re-verified against the current documents.

If a tool and a specification ever disagree, the specification wins.

Get in touch

Found a bug, have a feature idea, or want to talk about a partnership or advertising? Email us at ndeyekhadymbodj91@gmail.com, or visit our contact page.

Contact us

The build is deliberately boring in the places where boring is a feature. There is no session layer to expire, no job queue to drain, and no database schema to migrate, which means an outage on the hosting side leaves readers with a cached copy of a page rather than a half-rendered application. Static files also let the site be mirrored, archived or served from a different host without code changes, and they keep the attack surface limited to whatever the hosting provider and the browser itself expose. That trade-off cuts both ways. Anything requiring a server to make a decision, such as shared saved state or server-side rendering of user input, is outside the scope of these tools.

The specifications behind the tools on this page

The normative documents below back the claims on this page.