Pixefy - Responsive Design Checker

Preview and debug your website’s responsiveness across multiple devices in real-time, all inside one browser tab.

Pixefy helps you spot layout issues instantly and fine-tune designs with live editing tools – right as you build. It simplifies responsive testing by letting you preview, debug, and edit across multiple screen sizes in one place – no more switching tabs or resizing windows manually. 🚀 Key Features: ✔️ 🟢🟠 Live Responsive Previews – Test across multiple screen sizes side-by-side. Scroll, click, and interact on all screens simultaneously. Match real devices with optional browser bars, device mockups + native UI spacing. ✔️ 🟢🟠 Custom Screens & Presets – Create your own breakpoints, save them as reusable presets, or use popular device resolutions out of the box. ✔️ 🟢 Screen Management – Rearrange, stack (horizontal/vertical), rotate, or zoom screens globally for a flexible workspace. ✔️ 🟠 Projects – Save your entire workspace as a project: panes, edits, measurements, and settings. Auto-open Pixefy when you visit a project's site, and share projects with teammates. ✔️ 🟢🟠 Inspect & X-Ray – Inspect styles, edit attributes live, and debug layouts with Visual Box Model, grids, and X-Ray overlays. ✔️ 🟢🟠 CSS Debugging Tools – View/edit computed styles, switch any CSS declaration off to see what's underneath, trace values back to their clamp()/calc()/var() formulas and design tokens, measure distances, compare elements across breakpoints, and track all changes in the Activity Tab. ✔️ 🟠 W3C Validation – Run any page through the official W3C CSS and HTML validators without leaving your workspace – errors grouped with plain-language labels and line numbers. ✔️ 🟠 Tech Stack Detection – Instantly see the frameworks, CMS, hosting, and CDN behind any page. ✔️ 🟠 Content Editing – Instantly replace text or images, and check word/character counts directly on the page. ✔️ 🟠 Asset Downloads – Extract SVGs, PNGs, and other assets directly from Inspect Tool tabs. ✔️ 🟢 Screenshots & Annotations – Capture full pages, visible areas, or selected regions, then add notes, arrows, and highlights for clear, shareable feedback. ✔️ 🟠 AI & Issue Tracker Integrations – Connect Pixefy to Claude, Cursor, ChatGPT, and other AI tools via MCP, copy full page context for AI, or push your changes straight to Trello, Linear, and Azure DevOps. ✔️ 🟠 Design Comparison – Overlay a design image on the live page to spot pixel-level differences. ✔️ 🟠 User Agent Switching – Simulate different devices, browsers, or bots to see how your site adapts. ✔️ 🟠 Accessibility Tools – Test AA/AAA contrast ratios, extract all colors, and preview vision impairments with blindness simulations. ✔️ 🟢 Performance & Console Monitoring – Watch load metrics and console errors for every screen at a glance. ✔️ 🟢 Utilities – Live Dimension Widget (viewport width/height), reload with cleared cache, header bypass for sites that block embedding, copy any value or asset to clipboard. ✔️ 🟠 Themes – Switch between website's light and dark mode instantly. ✔️ 🟠 SEO Overview – Get a quick overview of key on-page SEO elements, including titles, meta descriptions, headings, and other essential page data. ✔️ 🟢 Touch Simulation – Simulate touch interactions to preview how websites behave on touch-based devices. Pixefy is regularly updated based on user feedback. Report issues or share ideas: https://feedback.pixefy.io/ See what's new: www.pixefy.io/changelog