A free browser-based developer tool for opening browser windows at exact pixel dimensions. Perfect for taking pixel-perfect screenshots for any device or resolution — no install required.
ViewPorter is a free developer tool that opens controlled popup windows at exact pixel dimensions, making pixel-perfect screenshots effortless for any device or resolution.
Developers and designers regularly need screenshots at precise viewport dimensions — for portfolio pieces, App Store previews, client deliverables, and design documentation. Manually resizing a browser window is frustratingly imprecise: OS chrome, snap zones, and lack of feedback mean your "1440×900" window is rarely actually 1440×900.
ViewPorter uses window.open() with explicit dimension parameters to launch a popup at exactly the width and height you specify — then exposes window.resizeTo() through a Resize button so you can adjust without reopening.
The tool is entirely client-side, zero-install, and works in any modern browser.
Set width and height to any value from 200–5000px. Fine-tune with arrow buttons or type exact values. A live dimension preview updates as you type.
One-click presets for the most common screenshot targets:
Lock the aspect ratio and adjust one dimension — the other updates proportionally to keep things consistent.
Enter any URL and it loads inside the popup on launch. Leave blank to open an empty window for manual navigation.
Adjust window dimensions without closing and reopening — useful for comparing designs across breakpoints without losing scroll position.
Practical, opinionated tips for capturing clean screenshots: hide DevTools first, disable scrollbars via a DevTools snippet, use native OS capture for shadow-free window screenshots, use GoFullPage for full-page captures.
ViewPorter is one of several free tools built for developers and designers:
The client needed a robust developer tools solution that could scale with their growing user base while maintaining a seamless user experience across all devices.
We built a modern application using Developer Tools and Screenshots, focusing on performance, accessibility, and a delightful user experience.
Category
Developer Tools
Technologies
Date
February 2026
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