What Are Placeholder Images?

What Are Placeholder Images?

Placeholder images are dynamically generated images used during development when real content is not yet available. They fill <img> tags in your layout so you can build and test responsive designs, card components, image galleries, and landing pages without waiting for real photography or artwork.

A placeholder image API generates these images on the fly through URL parameters. Instead of creating dummy images in Photoshop, you construct a URL like https://api.example.com/image/600x400 and get back an image of exactly that size. Change the URL, change the image -- no uploads, no CDN, no storage.

In 2026, placeholder image APIs have evolved beyond simple colored rectangles. Modern services offer custom text overlays, gradient backgrounds, format options (PNG, JPEG, WebP, SVG), and even AI-generated content. This guide compares the top free options and shows you how to integrate them into your workflow.

When to Use Placeholder Image APIs

• Frontend prototyping - Build out layouts with correct aspect ratios before real images are ready
• Design system documentation - Show image components at various sizes in your Storybook or style guide
• Email template testing - Test how images render across email clients without hosting real assets
• Database seeding - Populate development databases with realistic image URLs for testing
• API mocking - Return placeholder image URLs from mock APIs during frontend development
• Portfolio projects - Demo applications look polished even without real content
• CI/CD testing - Automated tests that need image assets without committing binary files to git

Placeholder Image API Comparison

CommandSector Image Generation API

The CommandSector Image Generation API at /api/image/* generates placeholder images with more customization than traditional services. Beyond basic size and color, it supports gradient backgrounds, multiple font families, and four output formats. And since it is part of the CommandSector suite, the same API key gives you access to 12 other APIs.

Key Features

• Any dimension - Generate images from 1x1 to 4000x4000 pixels
• Hex color control - Set background color, text color, or gradient stops with hex codes
• Custom text overlay - Add labels, dimensions, or custom messages
• Gradient backgrounds - Linear gradients with configurable direction and colors
• Four output formats - PNG for transparency, JPEG for photos, WebP for performance, SVG for scalability
• Font selection - Choose from multiple web-safe fonts for text overlays

URL Patterns & Parameters

Basic Placeholder

# Basic 600x400 placeholder
https://api.commandsector.in/api/image/generate?width=600&height=400&api_key=YOUR_KEY

# With custom background and text colors
https://api.commandsector.in/api/image/generate?width=600&height=400&bg_color=1a1a2e&text_color=e94560&api_key=YOUR_KEY

# With custom text
https://api.commandsector.in/api/image/generate?width=800&height=200&text=Hero+Banner&api_key=YOUR_KEY

# With gradient background
https://api.commandsector.in/api/image/generate?width=600&height=400&gradient=0f3460,e94560&api_key=YOUR_KEY

# SVG output for scalable graphics
https://api.commandsector.in/api/image/generate?width=300&height=300&format=svg&api_key=YOUR_KEY

# WebP for optimal web performance
https://api.commandsector.in/api/image/generate?width=1200&height=630&format=webp&text=OG+Image&api_key=YOUR_KEY

Common Size Presets

Code Examples

HTML - Direct Image Embedding

<!-- Basic placeholder in an img tag -->
<img
  src="https://api.commandsector.in/api/image/generate?width=400&height=300&api_key=YOUR_KEY"
  alt="Product placeholder"
  width="400"
  height="300"
/>

<!-- Card grid with labeled placeholders -->
<div style="display:grid;grid-template-columns:repeat(3,1fr);gap:16px">
  <img src="https://api.commandsector.in/api/image/generate?width=400&height=300&text=Card+1&bg_color=1a1a2e&api_key=YOUR_KEY" />
  <img src="https://api.commandsector.in/api/image/generate?width=400&height=300&text=Card+2&bg_color=16213e&api_key=YOUR_KEY" />
  <img src="https://api.commandsector.in/api/image/generate?width=400&height=300&text=Card+3&bg_color=0f3460&api_key=YOUR_KEY" />
</div>

JavaScript - Dynamic Placeholder Generator

function getPlaceholderUrl(width, height, options = {}) {
  const params = new URLSearchParams({
    width,
    height,
    api_key: "YOUR_KEY",
    ...options,
  });
  return `https://api.commandsector.in/api/image/generate?${params}`;
}

// Usage in a React component
function ProductCard({ product }) {
  const imageUrl = product.image || getPlaceholderUrl(400, 300, {
    text: product.name,
    bg_color: "161b22",
    text_color: "58a6ff",
  });

  return (
    <div className="card">
      <img src={imageUrl} alt={product.name} />
      <h3>{product.name}</h3>
      <p>{product.price}</p>
    </div>
  );
}

Python - Seed a Database with Placeholder Images

import requests

API_KEY = "YOUR_KEY"
BASE_URL = "https://api.commandsector.in/api/image/generate"

# Generate placeholder URLs for seeding a database
products = [
    {"name": "Laptop Pro", "width": 600, "height": 400},
    {"name": "Wireless Mouse", "width": 400, "height": 400},
    {"name": "USB-C Hub", "width": 600, "height": 300},
]

for product in products:
    image_url = (
        f"{BASE_URL}?width={product['width']}"
        f"&height={product['height']}"
        f"&text={product['name'].replace(' ', '+')}"
        f"&bg_color=0d1117&text_color=c9d1d9"
        f"&api_key={API_KEY}"
    )
    print(f"{product['name']}: {image_url}")

    # Or download the image directly
    response = requests.get(image_url)
    with open(f"{product['name'].lower().replace(' ', '_')}.png", "wb") as f:
        f.write(response.content)

cURL - Download a Placeholder Image

# Download a 1200x630 OG image with gradient background
curl -o og-image.png "https://api.commandsector.in/api/image/generate?width=1200&height=630&gradient=667eea,764ba2&text=My+Blog+Post&format=png&api_key=YOUR_KEY"

# Generate an SVG placeholder (scalable, tiny file size)
curl -o placeholder.svg "https://api.commandsector.in/api/image/generate?width=800&height=600&format=svg&text=SVG+Placeholder&api_key=YOUR_KEY"

Advanced Usage & Automation

Using in CSS as Background Images

/* Use as a CSS background image during development */
.hero-section {
  background-image: url("https://api.commandsector.in/api/image/generate?width=1920&height=800&gradient=0f3460,e94560&text=Hero+Section&api_key=YOUR_KEY");
  background-size: cover;
  background-position: center;
  min-height: 400px;
}

/* Responsive placeholder with CSS aspect-ratio */
.card-image {
  aspect-ratio: 4 / 3;
  background-image: url("https://api.commandsector.in/api/image/generate?width=400&height=300&bg_color=161b22&api_key=YOUR_KEY");
  background-size: cover;
}

Comparison with Other Services

If you are currently using placeholder.com or placehold.co, switching to the CommandSector Image API gives you gradient support, more font options, and the bonus of 12 other APIs under the same key. The URL patterns are different but equally simple. For most development workflows, the 100 requests/day free tier is more than enough since placeholder images are typically cached by the browser after the first load.

For production applications, replace the placeholder URLs with real image paths before deploying. A common pattern is to use environment variables:

// Use placeholder images in development, real images in production
const imageBase = process.env.NODE_ENV === "development"
  ? "https://api.commandsector.in/api/image/generate"
  : "https://cdn.yoursite.com/images";