Guides / Java
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 Java 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 java.net.URI;
import java.net.http.*;
import java.nio.file.*;
import java.time.Duration;
public class Render {
public static void main(String[] args) throws Exception {
String body = """
{"url": "https://example.com", "full_page": true, "format": "png"}""";
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("https://rasterkit.com/v1/screenshot"))
.timeout(Duration.ofSeconds(60))
.header("x-api-key", System.getenv("RASTERKIT_API_KEY"))
.header("content-type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(body))
.build();
HttpResponse<byte[]> res = HttpClient.newHttpClient()
.send(request, HttpResponse.BodyHandlers.ofByteArray());
if (res.statusCode() != 200) {
throw new RuntimeException("Render failed: " + res.statusCode() + " " + new String(res.body()));
}
Files.write(Path.of("screenshot.png"), res.body());
System.out.println("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.