Avoiding blocks

The most common support issue by far: the screenshot comes back blank, shows a "checking your browser" page, or returns a 403 / Access Denied. The site has detected automated traffic and blocked it.

Why it happens

Bot-protection services (Cloudflare, DataDome, PerimeterX) and simple 403 rules detect headless browsers and known datacenter IP ranges, then serve a challenge or block page instead of the real content.

Fix

Try these in order:

1. use_stealth — apply anti-detection measures so the browser looks like a normal one.
2. proxy — route the render through your own proxy ([user:pass@]address:port, Ultra plan). Or use_proxy to use the proxy configured on your project.

{  "url": "https://example.com",  "use_stealth": true,  "use_proxy": true}

If that doesn't work

• Use a residential proxy rather than a datacenter one — it's the single biggest factor for tough sites.
• Set a realistic user_agent.
• Block the scripts doing the detection with block_urls.
• If the page renders but looks broken rather than blocked, set engine_version to latest.