How to Convert HTML to an Image with an API (2026)

Converting HTML to an image is one of the most useful rendering operations in modern development. Social cards, invoices, OG images, email previews, and certificates — all start as HTML templates and need to become PNGs or JPEGs. This guide covers three approaches: a dedicated rendering API (fastest to ship), Puppeteer (the DIY standard), and a serverless function with Satori (for React-specific templates). Each includes working code you can copy and run. Method 1: Rendex API (Fastest) The Rendex HTML-to-image API handles browser rendering on Cloudflare's edge network. Pass HTML as a string, get back a PNG, JPEG, WebP, or PDF. No Chromium install, no infrastructure. # pip install rendex from rendex import Rendex from pathlib import Path rendex = Rendex ( " YOUR_API_KEY " ) html = """ <div style= " width:1200px;height:630px;display:flex;align-items:center; justify-content:center;background:linear-gradient(135deg,#667eea,#764ba2); font-family:system-ui;color:white;font-size:48px;font-wei