🖼️ placeholdr.dev

AI Placeholder Image API for Developers

Generate deterministic placeholder images from a single URL. No account, API key, or JavaScript.
Choose exact dimensions, prompt, style, and seed; finished images are cached globally.

Example landscape placeholder

Basic Usage

Drop this snippet directly into your HTML to request a unique placeholder on the fly.

<img src="https://placeholdr.dev/{width}x{height}/{prompt}" />

All Parameters

Add these parameters to the URL to customize the placeholder.

<img src="https://placeholdr.dev/{width}x{height}/{prompt}?style={style}&seed={int}" />

  • Height and Width: required, integers between 128 and 2048

  • Prompt: text description of the desired image ("space" by default)

  • Style: photographic (default), artistic, anime, oil-painting, 3d-render, cartoon

  • Seed: integer between 1 and 3 (1 by default) for alternative outputs

Examples

Real API calls
Minimalist modern office placeholder
https://placeholdr.dev/600x400/minimalist modern office
Anime cat placeholder
https://placeholdr.dev/320x320/cat?style=anime
3D camera placeholder
https://placeholdr.dev/1024x768/camera?style=3d-render&seed=3
Cartoon forest landscape placeholder
https://placeholdr.dev/800x450/forest landscape?style=cartoon

Why placeholdr.dev?

  • Cloudflare network: Powered by Cloudflare Workers at the edge with R2 backing so renders stay cached globally and load fast.
  • Flux model: Powered by Flux diffusion model for quality placeholder imagery.
  • Simple URL API: Works anywhere you can drop an <img> tag or background image.
  • Fast initial generation: Fresh prompts render in a few seconds, then stay cached in R2 for near-instant deterministic repeats.
  • Free to use: No accounts, no billing, just request a placeholder and ship.

Frequently Asked Questions

What happens on the first request?

A new URL returns a temporary SVG immediately while the final image is generated. Reload the page after a few seconds to see the finished image.

Do I need an account, API key, or JavaScript?

No. Use a normal <img> tag, CSS background, or any client that can request an image URL.

Are generated images deterministic?

Yes. Once an image has been generated, it will not change. The same URL always returns the same cached image. Change the seed from 1 to 3 for a different result.

Which dimensions and image formats are supported?

Width and height can each be from 128 to 2048 pixels, subject to supported aspect ratios.