Guides / Node.js
Maintaining your own headless-browser fleet for screenshots means babysitting Chromium versions, memory leaks, fonts, and proxy rules. RasterKit turns all of that into a single HTTPS call: send a URL from your Node.js code, get back finished image bytes.
The engine runs real Chromium, so modern CSS, web fonts and JavaScript-rendered pages come out exactly as users see them. Flags like full_page, device=mobile, dark_mode and block_cookie_banners handle the cases that make DIY screenshotting painful.
Sign up free (magic link, no card) — your key is shown right after sign-in. You get 100 renders/month free across screenshots, PDFs, and images.
import { writeFile } from 'node:fs/promises'
const res = await fetch('https://rasterkit.com/v1/screenshot', {
method: 'POST',
headers: {
'x-api-key': process.env.RASTERKIT_API_KEY,
'content-type': 'application/json',
},
body: JSON.stringify({"url": "https://example.com", "full_page": true, "format": "png"}),
})
if (!res.ok) throw new Error(`Render failed: ${res.status} ${await res.text()}`)
await writeFile('screenshot.png', Buffer.from(await res.arrayBuffer()))
console.log('Saved screenshot.png')The response body is the file itself — no JSON envelope to unwrap, no second download request. Errors come back as JSON with a stable error code.
The Screenshot API reference documents every parameter. The ones people reach for first:
full_page: true — capture the whole scroll height (lazy content auto-scrolled in)device: "mobile" — real iPhone-class viewport and user agentdark_mode: true — render with prefers-color-scheme: darkcache_ttl: 86400 — repeat captures become instant and freePass "full_page": true. RasterKit auto-scrolls the page first so lazy-loaded images and infinite-scroll content are included.
Yes — every render runs in real Chromium with JS enabled. Use wait_until: "networkidle", wait_for_selector, or delay_ms for late-rendering apps.
Typical p50 is 1.5–3 s for a normal page (sync request). Add cache_ttl and repeated captures of the same URL return instantly and free.