How to Choose the Right Screenshot Viewport: A Decision Guide

Every screenshot starts with a viewport choice. Pick the wrong size and your capture looks stretched, cropped, or blurry on the target device. This guide doesn't list every device dimension — for that, see our 2026 Device Viewport Reference. Instead, it helps you decide which viewport to use based on your screenshot's purpose.

Choosing the Right Size

By Purpose

Purpose	Recommended	Why
Documentation	1280 × 800	Fits most screens
Marketing	1920 × 1080	High quality
Social media	1200 × 630	OG image standard
Mobile screenshots	375 × 667	Common mobile size
Responsive testing	Multiple	Cover breakpoints

By Responsive Breakpoint

Common CSS breakpoints:

const breakpoints = {
  mobile: { width: 375, height: 667 },
  tablet: { width: 768, height: 1024 },
  laptop: { width: 1024, height: 768 },
  desktop: { width: 1280, height: 800 },
  largeDesktop: { width: 1920, height: 1080 },
};

Implementation

Basic Usage

const response = await fetch('https://api.screenshotly.app/screenshot', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    url: 'https://example.com',
    viewport: {
      width: 1920,
      height: 1080,
    },
  }),
});

Device Presets

Use device presets for convenience:

{
  url: 'https://example.com',
  device: 'desktop',  // Uses standard desktop viewport
}

{
  url: 'https://example.com',
  device: 'mobile',  // Uses iPhone 12 viewport
}

{
  url: 'https://example.com',
  device: 'tablet',  // Uses iPad viewport
}

Custom Devices

Define specific device characteristics:

{
  url: 'https://example.com',
  viewport: {
    width: 390,
    height: 844,
  },
  deviceScaleFactor: 3,  // Retina display
  isMobile: true,
  hasTouch: true,
}

Aspect Ratios

Common Ratios

Ratio	Description	Example Sizes
16:9	Widescreen	1920×1080, 1280×720
16:10	MacBook	1440×900, 1280×800
4:3	Traditional	1024×768, 800×600
1.91:1	OG Image	1200×630
1:1	Square	1080×1080
9:16	Portrait video	1080×1920

Maintaining Aspect Ratio

When resizing, maintain ratio:

function calculateHeight(width, aspectRatio) {
  const [w, h] = aspectRatio.split(':').map(Number);
  return Math.round(width * (h / w));
}

// 16:9 at 1280 width
const height = calculateHeight(1280, '16:9'); // 720

Device Scale Factor

Device scale factor (DPR) affects image quality:

DPR	Device Type	Effective Resolution
1x	Standard displays	1:1 pixel ratio
2x	Retina, most phones	2× pixel density
3x	iPhone Plus/Max	3× pixel density

High-DPI Screenshots

{
  viewport: {
    width: 375,
    height: 667,
  },
  deviceScaleFactor: 2,  // 750×1334 actual pixels
}

Result: 375×667 CSS pixels, but 750×1334 actual image pixels.

Full Page Captures

For full-page screenshots, height becomes less relevant:

{
  url: 'https://example.com',
  viewport: { width: 1280 },  // Only width matters
  fullPage: true,  // Height auto-determined by content
}

Maximum Height

Some pages are very long. Set a cap:

{
  url: 'https://example.com',
  fullPage: true,
  maxHeight: 10000,  // Cap at 10,000 pixels
}

When to Capture Multiple Viewports

If your goal is responsive testing or cross-device QA, you need more than one viewport. The minimum set for most projects:

Band	Recommended Width	Why
Small phone	375px	iPhone SE baseline
Standard phone	390–412px	Covers 80%+ of mobile traffic
Tablet	768px	iPad portrait breakpoint
Desktop	1920px	Full HD standard

For a complete list of 50+ device dimensions with copy-paste code, see the 2026 Device Viewport Reference. For CI/CD integration and visual regression workflows, see Mobile Screenshot Optimization.

Common Mistakes

1. Using Arbitrary Heights

Heights too short cut off content. Too tall wastes resources.

Fix: Use standard aspect ratios or fullPage: true

2. Ignoring Responsive Design

Desktop-only screenshots miss mobile issues.

Fix: Capture at multiple breakpoints

3. Wrong DPR for Platform

Low DPR looks blurry on retina devices.

Fix: Use deviceScaleFactor: 2 for marketing images

4. Landscape vs Portrait

Mobile sites may look different in each.

Fix: Consider both orientations:

// Portrait
{ width: 375, height: 667 }

// Landscape  
{ width: 667, height: 375 }

Best Practices

1. Match Your Audience

Check analytics for actual visitor devices:

• Google Analytics → Audience → Technology → Browser & OS
• Hotjar → Device type breakdown

2. Use Standard Sizes

Stick to common breakpoints:

• 375px (mobile)
• 768px (tablet)
• 1280px (laptop)
• 1920px (desktop)

3. Document Your Standards

Create a config for consistency:

// screenshot-config.js
export const viewportStandards = {
  documentation: { width: 1280, height: 800 },
  marketing: { width: 1920, height: 1080, deviceScaleFactor: 2 },
  social: { width: 1200, height: 630 },
  mobile: { width: 375, height: 667, isMobile: true },
};

4. Test Before Production

New viewports may reveal unexpected layouts. Always review screenshots before publishing.

Decision Cheat Sheet

Your goal	Viewport	DPR	Format
Docs / help center	1280 × 800	1	PNG
Marketing hero	1920 × 1080	2	PNG
Social / OG image	1200 × 630	1	JPEG 85%
Mobile app store	430 × 932	3	PNG
Full-page export	Width only + fullPage: true	1	PDF/PNG

Use device presets for convenience, custom viewports for precision.

---

Ready to capture at any viewport?

Get your free API key → - 100 free screenshots to get started.

• 2026 Device Viewport Reference → — 50+ device dimensions
• Mobile Screenshot Optimization → — CI/CD, visual regression, device emulation
• Try configurations in our API Playground →