renderpix API

Convert HTML/CSS to pixel-perfect images with a single API call. Base URL: https://renderpix.dev

Authentication

All requests require an API key via X-API-Key header:

curl -H "X-API-Key: rpx_your_key" https://renderpix.dev/v1/render

Get your key from the Dashboard. Also accepted as ?api_key=rpx_... query param.

Quick start

curl -X POST https://renderpix.dev/v1/render \
  -H "X-API-Key: rpx_your_key" \
  -H "Content-Type: application/json" \
  -d '{"html":"<h1 style=\"color:red\">Hello</h1>"}' \
  -o hello.png

npm install renderpix

import { RenderPix } from 'renderpix'
import fs from 'fs'

const client = new RenderPix({ apiKey: 'rpx_your_key' })

const result = await client.render({
  html: '<h1 style="color:red">Hello</h1>',
  width: 1200,
  height: 630,
  format: 'png',
})

fs.writeFileSync('output.png', result.image)
console.log(`Rendered in ${result.renderTime}ms`)

POST/v1/render

Convert HTML/CSS to an image.

Request body (JSON)

Response headers

GET/v1/screenshot

Screenshot any public URL.

curl "https://renderpix.dev/v1/screenshot?url=https://stripe.com&api_key=rpx_your_key" -o stripe.png

Query parameters

POST/v1/batch

Render multiple HTML items in a single API call. Each item is processed independently — a failed item doesn't affect others (partial failure support).

Plan limits: Free: not available  ·  Starter: max 10 items  ·  Pro: max 50 items  ·  Scale: max 100 items

Request

POST /v1/batch
X-API-Key: rpx_your_key
Content-Type: application/json

{
  "items": [
    {
      "html": "<div style='background:#1a1a2e;color:white;padding:40px;font-size:32px'>Slide 1</div>",
      "width": 1080,
      "height": 1350,
      "format": "png",
      "vars": { "title": "Slide 1" }
    },
    {
      "html": "<div style='background:#16213e;color:white;padding:40px;font-size:32px'>Slide 2</div>",
      "width": 1080,
      "height": 1350,
      "format": "jpeg",
      "quality": 85
    }
  ],
  "callback_url": "https://your-app.com/webhook"
}

Response — success (HTTP 200)

{
  "results": [
    {
      "index": 0,
      "success": true,
      "image": "data:image/png;base64,iVBORw0KGgo...",
      "format": "png",
      "width": 1080,
      "height": 1350,
      "duration_ms": 312
    },
    {
      "index": 1,
      "success": true,
      "image": "data:image/jpeg;base64,/9j/4AAQSkZJRg...",
      "format": "jpeg",
      "width": 1080,
      "height": 1350,
      "duration_ms": 287
    }
  ],
  "total": 2,
  "succeeded": 2,
  "failed": 0
}

Response — partial failure (HTTP 207)

{
  "results": [
    { "index": 0, "success": true, "image": "...", "duration_ms": 290 },
    { "index": 1, "success": false, "error": "Render timeout exceeded" }
  ],
  "total": 2,
  "succeeded": 1,
  "failed": 1
}

Error codes

Template Variables

Inject dynamic content into HTML using {{key}} syntax. The vars object replaces each key-value pair in the HTML before rendering. Available on all plans.

Request example

POST /v1/render
X-API-Key: rpx_your_key
Content-Type: application/json

{
  "html": "<div style='font-family:sans-serif;padding:40px;background:#0f172a;color:white'>
             <h1 style='color:#22d3ee'>{{title}}</h1>
             <p>{{description}}</p>
             <span style='color:#a78bfa'>{{date}}</span>
           </div>",
  "width": 1200,
  "height": 630,
  "format": "png",
  "vars": {
    "title": "My Blog Post",
    "description": "An introduction to HTML-to-image APIs",
    "date": "June 2026"
  }
}

Notes

Async Rendering

Pass a callback_url to start a render asynchronously. The API immediately returns 202 Accepted; when the render completes, it POSTs the result to your URL. Available on Pro and Scale plans.

Request

POST /v1/render
X-API-Key: rpx_your_key
Content-Type: application/json

{
  "html": "<div>...</div>",
  "width": 1200,
  "height": 630,
  "format": "png",
  "callback_url": "https://your-app.com/renderpix-webhook"
}

Immediate response (HTTP 202)

{
  "status": "accepted",
  "message": "Render started. Result will be posted to your callback_url."
}

Callback payload (POSTed to your webhook when render completes)

POST https://your-app.com/renderpix-webhook
Content-Type: application/json
X-RenderPix-Event: render.complete

{
  "success": true,
  "image": "data:image/png;base64,iVBORw0KGgo...",
  "format": "png",
  "width": 1200,
  "height": 630,
  "duration_ms": 834
}

Notes

waitUntil Parameter

Controls when Playwright considers the page ready before capturing the screenshot. Default: load. Available on all plans.

Values

Example

{
  "html": "<link href='https://fonts.googleapis.com/...' rel='stylesheet'><div>...</div>",
  "width": 1200,
  "height": 630,
  "waitUntil": "networkidle"
}

GET/v1/og-image

Generate a ready-to-use Open Graph image from text. No HTML required. Authentication is optional — unauthenticated requests include a watermark and are limited to 10 requests/minute; authenticated requests count against your plan.

curl "https://renderpix.dev/v1/og-image?title=Hello+World&domain=mysite.com&theme=dark&api_key=rpx_your_key" -o og.png

Query parameters

Response is a 1200×630 PNG — the standard Open Graph image size.

Error codes

Rate limits & plan comparison

All plans: 100 requests/minute per API key.