About Grout - Professional Image Generation API

Grout is a high-performance HTTP service written in Go that generates images on-demand. Whether you need user avatars with initials or placeholder images for your designs, Grout delivers them instantly with smart caching and multiple format support. Built for developers who need reliable, fast image generation without complex dependencies.

Key Features:

Generate circular or square avatars with user initials automatically
Create custom placeholder images with any dimensions and text
Support for multiple formats: WebP, PNG, JPG, and GIF
Smart in-memory LRU caching for optimal performance and speed
ETag support for conditional requests and CDN optimization
Customizable colors, sizes, and styles via simple URL parameters
Free, open-source, and self-hostable for complete control

Avatar API Examples - Generate User Initials Images

Square Avatar

https://grout.in/avatar/John+Doe?size=128

Round Avatar (Random Color)

https://grout.in/avatar/Jane+Smith?size=128&rounded=true&background=random

Custom Colors & Bold

https://grout.in/avatar/Alex+Johnson?size=128&rounded=true&bold=true&background=3498db&color=ffffff

Avatar URL Parameters - Customize Your Images

Parameter	Type	Default	Description
`name`	string	"John Doe"	Name to extract initials from (can be in path or query)
`size`	integer	128	Size in pixels (width and height)
`background`	hex/random	f0e9e9	Background color (hex without #) or "random" for deterministic color
`color`	hex	auto-contrast	Text color (hex without #), auto-calculated if not provided
`rounded`	boolean	false	Set to "true" for circular avatars
`bold`	boolean	false	Set to "true" for bold font
extension	.png/.jpg/.gif/.webp	.webp	Image format (append to name: /avatar/Name.png)

Placeholder Image API Examples - Dynamic Placeholder Generator

Basic Placeholder

https://grout.in/placeholder/300x200

Custom placeholder with hero text and dark background - Grout API example

Custom Text & Colors

https://grout.in/placeholder/300x200?text=Hero+Image&bg=2c3e50&color=ecf0f1

Gradient placeholder image red to blue - Grout gradient generator example

Gradient Background

https://grout.in/placeholder/300x200?bg=e74c3c,3498db&text=Gradient

Placeholder URL Parameters - Full Customization Options

Parameter	Type	Default	Description
dimensions	path	128x128	Image dimensions in format: /placeholder/{width}x{height}
`w`	integer	128	Width in pixels (alternative to path dimensions)
`h`	integer	128	Height in pixels (alternative to path dimensions)
`text`	string	"{width} x {height}"	Text to display on the placeholder
`bg`	hex	cccccc	Background color (hex without #). Use comma-separated values for gradients (e.g., ff0000,0000ff)
`color`	hex	auto-contrast	Text color (hex without #), auto-calculated if not provided
extension	.png/.jpg/.gif/.webp	.webp	Image format (append to dimensions: /placeholder/300x200.png)

Why Choose Grout for Image Generation?

Grout is a powerful, open-source image generation service designed for modern web developers who need reliable avatar and placeholder image solutions. Whether you're building a social platform, e-commerce site, or web application, Grout provides enterprise-grade image generation capabilities with zero configuration required.

Perfect for Multiple Use Cases

Web Applications

Generate dynamic user avatars for profile pictures, comment sections, and user directories. Our avatar generator automatically creates beautiful initials-based images for any user name.

Design & Prototyping

Create placeholder images for mockups, wireframes, and design systems. Perfect for designers and developers who need quick placeholder graphics with custom dimensions and text.

E-commerce Platforms

Display temporary product images while loading or when images are unavailable. Generate consistent placeholder images that match your brand colors and maintain user experience.

Content Management Systems

Automatically generate author avatars, default post images, and media placeholders. Integrate seamlessly with WordPress, Drupal, or custom CMS solutions via REST API.

Social Media Integration

Create profile pictures for social login, user badges, and community features. Support for circular avatars perfect for social media platforms and messaging apps.

Mobile Applications

Lightweight API for generating images in mobile apps (iOS, Android, React Native). WebP format support ensures optimal performance for mobile networks.

Technical Features & Benefits

⚡ High Performance

Built with Go for blazing-fast image generation. In-memory LRU caching ensures sub-millisecond response times for cached images. Perfect for high-traffic websites and applications.

🎨 Multiple Image Formats

Native support for WebP, PNG, JPG, GIF, and SVG formats. Choose the best format for your use case - WebP for modern browsers, PNG for transparency, JPG for photos, SVG for scalability.

🔧 Simple REST API

Easy-to-use RESTful API with intuitive URL parameters. No authentication required, no API keys, no rate limits. Just simple HTTP GET requests to generate images on-demand.

🎯 Customizable Design

Full control over colors, sizes, shapes, and text. Support for gradient backgrounds, custom fonts (bold/regular), circular or square avatars, and auto-contrast text colors.

📦 Self-Hosted Solution

Deploy on your own infrastructure for complete data privacy and control. Docker support makes deployment easy on any platform - AWS, Google Cloud, Azure, or on-premises.

🚀 CDN-Ready

Immutable cache headers and ETag support optimize CDN caching. Deploy behind Cloudflare, AWS CloudFront, or Fastly for global edge caching and ultra-fast delivery.

Easy Integration for Developers

Grout integrates seamlessly with any web technology stack. Whether you're using React, Vue, Angular, vanilla JavaScript, or server-side frameworks like Django, Rails, Laravel, or Express.js, Grout works out of the box.

Quick Integration Examples

HTML / Vanilla JavaScript

<img src="https://grout.in/avatar/John+Doe.webp?size=200&rounded=true" 
     alt="User Avatar">

React / Next.js

const Avatar = ({ name, size = 128 }) => (
  <img 
    src={`https://grout.in/avatar/${name}.webp?size=${size}&rounded=true`}
    alt={`${name} avatar`}
  />
);

Vue.js

<template>
  <img :src="avatarUrl" :alt="`${name} avatar`">
</template>

<script>
export default {
  computed: {
    avatarUrl() {
      return `https://grout.in/avatar/${this.name}.webp?size=150&rounded=true`;
    }
  }
};
</script>

Python / Django

# In your template
<img src="https://grout.in/avatar/{{ user.name }}.webp?size=128&rounded=true" 
     alt="User avatar">

# Or generate URL in views
avatar_url = f"https://grout.in/avatar/{user.name}.webp?size=128&rounded=true"

Need more integration examples? Check out our GitHub repository for comprehensive documentation, code samples, and community contributions.

Free, Open Source, and Production-Ready

Grout is completely free to use and licensed under MIT. Whether you're a hobbyist building a side project or an enterprise deploying at scale, Grout provides professional-grade image generation without licensing costs or vendor lock-in.

As a lightweight, self-hosted solution, Grout gives you complete control over your avatar and placeholder image generation. Built with Go for exceptional performance, our HTTP image API supports all modern formats including WebP, PNG, JPG, and GIF. The REST API requires no authentication or API keys, making it perfect for rapid development and prototyping. Whether you need a profile picture generator for your web application, dynamic placeholder images for your CMS, or custom avatars for your mobile app, Grout delivers production-ready results with zero configuration.