---
type: Article
title: "Crawl Budget Optimization for JavaScript Sites"
description: "What crawl budget really is, why JS-heavy pages get discovered but not indexed, and the prerendering patterns that lift crawl efficiency without origin cost."
resource: "https://prerendering.com/blog/crawl-budget-optimization-for-javascript-sites"
tags: [crawl budget, indexation, prerendering, javascript seo, technical seo]
timestamp: 2026-04-13T00:00:00Z
---

# Crawl Budget Optimization for JavaScript Sites

What crawl budget really is, why JS-heavy pages get discovered but not indexed, and the prerendering patterns that lift crawl efficiency without origin cost.

A technical guide to crawl budget, discovered-not-indexed failures, server response times, render-blocking JavaScript, and prerendering patterns that improve indexation efficiency.

## Details

- Category: Technical SEO
- Reading time: 12 min
- Topics: Crawl Budget, Indexation, Prerendering, JavaScript SEO, Technical SEO

## Related

- [Technical SEO audit](/services/technical-seo-audit.md)
- [JavaScript SEO](/services/javascript-seo.md)
- [Prerendering](/services/prerendering.md)
- [Bot Detection and Offloading via Prerendering](/blog/bot-detection-and-offloading-bot-visits.md)