Imageslot API Documentation

The Imageslot API enables fast, flexible placeholder image generation for web development, design, and prototyping. Dynamically create, resize, and customize images on-the-fly—perfect for rapid workflows, responsive layouts, and seamless integration with your favorite stacks. Dive in to learn how to use Imageslot’s RESTful image API for dynamic resizing, text overlays, format conversion, accessibility, and more.

Visual map of the Imageslot documentation structure: API Reference, Parameters, Examples, Integrations

Imageslot API Capabilities

Dynamically generate images with custom size, text, background, and format – in a single API call.
Serve instant placeholder images for web, apps, emails, mockups, and UI kits.
Overlay readable, auto-sized text onto images, with options for font, color, and shadow.
On-the-fly format conversion: JPG, PNG, GIF – switch via URL parameter.
Responsive generation: match device size, aspect ratio, or design breakpoints easily.
Seamless integration: RESTful endpoint for use in HTML, CSS, JS, React, Vue, WordPress, and more.
No signup or API key needed for basic use. Pro features may require authentication (see below).

What makes Imageslot different? Clean URLs, real-time generation, and robust customization—no static asset management required.

Getting Started: Your First Imageslot API Call

Construct your API endpoint: All placeholder images use the /v1/ endpoint. The basic pattern is:
https://imageslot.com/v1/{width}x{height}?filetype=png
Add parameters: Set text, background, foreground, and other options using URL parameters.
E.g., ?text=Hello&bg=173559&fg=fff
Paste your URL anywhere: Use as an <img src=...>, CSS background-image, or fetch in your app.
Advanced? See Key Concepts and Examples for more.

Sample API Request (HTML):

<img src="https://imageslot.com/v1/400x200?text=Docs+Demo&bg=ececec&fg=23272f&filetype=png" alt="Docs Demo">

Pro tip: No API key required for core features. For advanced usage, see the Advanced Features section.

Key Concepts: URL Parameters, Sizing & Formats

What is an Image Slot?

An image slot is a dynamically generated placeholder image, delivered via a RESTful API endpoint, tailored to your requested size, color, text, and format. Each API call "fills" your slot with custom content.

How URL Parameters Work

Customize any image by adding query parameters (e.g., ?text=Banner&bg=173559&fg=fff&filetype=png). Parameters are documented in the API Reference and URL Parameters pages.

width x height: e.g., 800x400
bg: background color (hex, no #)
fg: text color (hex, no #)
text: custom overlay text
filetype: png, jpg, jpeg, or gif

Supported File Formats

PNG: Best for sharpness, transparency.
JPG/JPEG: Small file size, no transparency.
GIF: Simple animation, solid colors.

Sizing & Responsiveness

Specify any size up to 2000x2000px. For responsive design, use srcset or generate multiple sizes. See Image Sizing Guide.

Accessibility Features

High-contrast color options, ARIA-ready markup, and descriptive alt text help make placeholders accessible. Learn more in Accessibility Features.

Usage Examples: Copy-Paste Code & Live Previews

<img src="https://imageslot.com/v1/800x400?text=Banner&bg=173559&fg=fff&filetype=png" alt="API Example">

{`<img src=\"https://imageslot.com/v1/600x300?text=React+Demo&bg=1A726B&fg=fff&filetype=jpg\" alt=\"React Placeholder\" />`}

<img :src="`https://imageslot.com/v1/400x200?text=Vue+Image&bg=3DA35D&fg=fff&filetype=png`" alt="Vue Placeholder">

[image src="https://imageslot.com/v1/320x120?text=WP+Shortcode&bg=ececec&fg=23272f&filetype=png" alt="WP Placeholder"]

Example of live API image preview for Imageslot

Overlay Custom Text:

<img src="https://imageslot.com/v1/300x100?text=Sale+Banner&filetype=jpg" alt="Sale Banner">

Transparent PNG Background:

<img src="https://imageslot.com/v1/400x200?bg=transparent&filetype=png" alt="Transparent Background">

High-Resolution (Retina):

<img src="https://imageslot.com/v1/1600x900?text=2x+Image&filetype=png" width="800" height="450" alt="Retina">

Integration Guides: WordPress, React, Vue, Figma & More

WordPress

Add Imageslot placeholders via HTML blocks, Gutenberg, or shortcodes. See full WordPress integration guide.

React

Use Imageslot in React components via dynamic src. Supports stateful image placeholders and live updates.
See full React integration guide.

Vue

Easily bind Imageslot URLs in Vue templates and components. See Vue integration guide.

Figma

Paste Imageslot URLs into Figma's Image Fill or use plugins for rapid placeholder swapping. See Figma integration guide.

Need more? Explore all supported integrations, including Next.js, Angular, and popular CMSes.

Advanced Features, Customization & Best Practices

Customization Options

Set font size, bold, italic for overlay text.
Apply shadow color for better readability.
Generate transparent backgrounds with bg=transparent and filetype=png.
Use multiple formats for optimal performance (PNG, JPG, GIF).

Performance & Caching

All Imageslot images are served via CDN for fast global delivery. Use browser and CDN caching for best speed. See speed optimization tips.

Accessibility & SEO

Choose high-contrast color combinations for legibility.
Always set descriptive alt text for accessibility.
Match placeholder aspect ratio to your final images to avoid layout shifts.
Use width and height attributes in HTML for core web vitals.

Rate Limits & Fair Use

Imageslot is free for moderate use. For high-volume or commercial projects, review the terms and rate limits.

Troubleshooting & Best Practices

Image not displaying? Double-check the URL format, parameter spelling, and ensure you’ve used a supported filetype.
Slow loading? Use smaller dimensions and JPG format for fastest results. Check your CDN and browser cache.
Text not visible? Adjust fg, bg, and shadow to improve contrast. Avoid similar colors.
Need responsive images? Use srcset for multiple sizes, or generate dynamic URLs in your app.
Accessibility issues? Set descriptive alt text and use ARIA attributes as needed.

Checklist: Validate URLs, optimize for speed, match aspect ratios, and always provide alt text for accessible, high-performance image placeholders.

FAQ: Imageslot API Documentation & Usage

Construct your API URL with the desired widthxheight directly in the path (e.g., /v1/800x400). Imageslot will generate an image at those exact dimensions. You can change size simply by editing the URL, making it ideal for responsive design and variable layouts. Combine this with srcset in HTML or dynamic URL generation in your app for seamless responsive image workflows.

Imageslot is designed to be universal: simply paste the API URL into any <img> tag, or generate it dynamically in your framework. Dedicated guides are available for WordPress, React, Vue, and Figma. See the Integration Guides section above for details.

Add parameters to the API URL to control every aspect of the image: ?text=Hello&bg=173559&fg=fff&filetype=png. You can set font size, bold/italic, shadow color, and more. See the API Reference and URL Parameters pages for a full list of options and usage notes.

For fastest loads, use minimal dimensions and JPG or GIF for non-critical visuals. Cache responses via browser and CDN, and minimize unnecessary requests. Always set width and height in HTML to avoid layout shifts, and use srcset for high-DPI (retina) displays. See the image speed guide for more tips.

Double-check for typos in parameter names and values, and be sure to use supported extensions and formats. If images fail to load, test your URL in a browser first. For persistent issues, review the troubleshooting guide and the Troubleshooting section above for step-by-step debugging advice.

For most users, Imageslot is free and unrestricted for low to moderate traffic. High-volume or automated usage may be subject to rate limits. For commercial or high-load applications, see the terms of service and API Reference for current limits and fair use policies.

Yes—Imageslot supports high-contrast color options, ARIA-compliant markup, and encourages descriptive alt text for all generated placeholders. See Accessibility Features for specific guidance on building accessible user interfaces with Imageslot images.