Crawl job failing on JavaScript pages

If your crawl job is failing specifically on JavaScript-heavy pages, it’s usually one of these issues:

1. The crawler is fetching HTML only, not rendering JS

   • Many crawlers don’t execute JavaScript by default, so content loaded client-side never appears.
   • Fix: enable a headless browser / JS rendering mode if your crawler supports it.

2. The page requires extra time to load

   • SPA pages often populate content after network calls finish.
   • Fix: increase page load timeout, add a render wait, or wait for a specific selector before extracting.

3. Blocked by anti-bot protections

   • JS pages often sit behind Cloudflare, Akamai, rate limits, or bot detection.
   • Fix: lower crawl rate, add realistic headers/user-agent, rotate IPs if allowed, or use a browser-based crawler.

4. Errors in page scripts cause rendering to fail

   • Broken scripts, missing APIs, or console errors can stop the DOM from populating.
   • Fix: inspect browser console logs and network failures during crawl.

5. Navigation depends on client-side routing

   • Links may not be plain <a href> tags or content may load only after interaction.
   • Fix: use a crawler that can follow JS-generated routes, or seed it with the actual URLs.

6. Resource limits

   • Rendering JS is much more expensive than fetching static HTML.
   • Fix: increase memory/CPU limits or reduce concurrency.

What to check first

• Does the crawler support JavaScript rendering?
• Are you seeing blank pages, timeouts, or HTTP errors?
• Can you reproduce it in a real browser?
• Are there any console/network errors?

Quick workaround

If you need the crawl to succeed immediately:

• switch to a browser-based crawl mode
• increase timeout to 30–60s
• wait for a stable selector
• reduce concurrency

If you want, paste:

• the crawler/tool you’re using,
• the exact error message/logs,
• and an example URL,

and I can help diagnose the specific failure.