Frontend Developer Toolkit
Everything a frontend developer reaches for daily — JSON validators, CSS generators, color tools, image optimizers, SEO tag builders, and API utilities — collected in one place. Every tool runs entirely in your browser: no files are uploaded to any server, no account required, no tracking.
Open JSON Formatter→Featured Tool
All Tools (35)
Parse, validate, format, and minify JSON
Test regular expressions with live match highlighting
Pretty-print HTML markup
Minify CSS with clean-css — strip whitespace, merge rules, and shorten values
Minify JavaScript with Terser — mangle, compress, and strip whitespace
Minify HTML — collapse whitespace, remove comments, and shrink inline CSS and JS
Format minified or ugly JavaScript with adjustable indent and brace style
Format minified or compressed CSS with adjustable indent
Live HTML, CSS, and JavaScript playground in a sandboxed iframe
Run JSONPath expressions against any JSON document and inspect the matched paths and values
Validate JSON documents against a JSON Schema (Draft 2020-12) and see precise errors
Generate TypeScript interfaces or type aliases from any JSON sample
Pick colors and convert across HEX, RGB, HSL, OKLCH
Score contrast against WCAG AA and AAA standards
Build tonal, complementary, triadic, and tetradic palettes
Convert any color between HEX, RGB, HSL, HSV, CMYK, and OKLCH side-by-side
Build linear and radial CSS gradients with live preview
Stack multiple shadow layers with X/Y/blur/spread
Per-corner elliptical border-radius with live preview
Draggable timing-function editor with animated preview
Build CSS Grid layouts visually — adjust columns, rows, and gap with live preview
Experiment with flex-direction, justify-content, align-items, and wrap with a live preview
Generate frosted-glass CSS with live preview — backdrop-filter blur and rounded borders
Generate soft-UI box-shadow CSS for flat, concave, convex, or pressed shapes
Draw polygon clip-paths and copy the CSS
Convert between px / rem / em / pt / % / vw / vh / ch
Re-encode images at lower quality and dimensions
Convert images between PNG, JPG, WebP, AVIF — all in your browser
Strip whitespace, comments, and bloat from SVGs
Generate favicons + PWA manifest in a downloadable zip
Generate Open Graph + Twitter + meta tag blocks
Preview how a URL renders on Facebook, Twitter, LinkedIn
Generate Schema.org JSON-LD for Articles, Products, Events, FAQs, Organizations and more — improve rich-result eligibility
Send HTTP requests to CORS-enabled APIs and inspect responses — runs in your browser
Convert cURL commands to JavaScript fetch, axios, Python requests, Node.js, or PowerShell
Workflow: Build a Polished Landing-Page Hero
A concrete example of how these tools fit together when building a hero section from scratch.
Design the background gradient — Gradient Generator
Pick your colors and direction, then copy the ready-to-paste CSS.
Tune the CTA hover easing — Cubic-Bezier Editor
Drag the control points and preview the animation before committing the cubic-bezier() value.
Verify WCAG contrast on text-over-gradient — Contrast Checker
Paste your foreground and background colors to confirm AA/AAA compliance.
Optimize the hero image and inline SVG — Image Compressor + SVG Optimizer
Compress the raster hero image, then strip whitespace and metadata from any SVG illustrations.
Generate meta tags and Open Graph markup — Meta Tag Generator
Build the full <head> tag block — title, description, OG, and Twitter Card.
Preview the social share card — Open Graph Preview
Check exactly how the page will appear when shared on Facebook, Twitter, and LinkedIn.