```yaml
product: AlterLab
title: "Cache Busting — Web Scraping Glossary | AlterLab"
comparison_context: "AlterLab is an alternative to Firecrawl, ScrapingBee, and Bright Data."
source_url: https://alterlab.io/glossary/cache-busting
```

protocol

# Cache Busting

Cache busting forces a fresh server request by adding a unique query parameter or modifying the URL so that cached responses are bypassed and current content is fetched.

HTTP caches and CDNs store responses keyed by URL. Adding a unique query parameter — a timestamp, random value, or content hash — to a URL effectively creates a new cache key, forcing every cache layer between the client and the origin server to fetch a fresh copy. This is useful when scraping content that changes frequently and must not be served stale from intermediate caches.

For scrapers monitoring content for changes, appending `?_t=` with the current Unix timestamp ensures each request goes to the origin. However, this also increases origin server load and may trigger rate limits — use sparingly and only when freshness is critical.

Cache busting is also used by web developers to force browsers to load updated JavaScript and CSS bundles after a deployment: the asset URL includes a content hash (`main.abc123.js`) that changes with each build, guaranteeing the browser fetches the new version rather than serving the cached old one.

### What is Cache Busting?

Cache busting forces a fresh server request by adding a unique query parameter or modifying the URL so that cached responses are bypassed and current content is fetched.

### How does AlterLab handle Cache Busting?

Cache busting is also used by web developers to force browsers to load updated JavaScript and CSS bundles after a deployment: the asset URL includes a content hash (`main.abc123.js`) that changes with each build, guaranteeing the browser fetches the new version rather than serving the cached old one.

## Examples

```
import time, requests

# Force a fresh response by appending a timestamp parameter
url = f"https://example.com/prices?_nocache={int(time.time())}"
response = requests.get(url)
```

## Related Terms

[HTTP CacheHTTP caching stores copies of responses at the client or an intermediate proxy, allowing subsequent requests for the same resource to be served without a full server round-trip.](https://alterlab.io/glossary/http-cache)[CachingStoring copies of web responses to serve repeat requests faster, which can cause scrapers to receive stale data instead of live content.](https://alterlab.io/glossary/caching)[Content Delivery Network (CDN)A distributed network of servers that delivers web content from locations geographically close to the user, often where anti-bot protection is deployed.](https://alterlab.io/glossary/content-delivery-network)[Data FreshnessData freshness measures how recently scraped data was collected relative to the actual source, a critical metric for price monitoring, news aggregation, and inventory tracking.](https://alterlab.io/glossary/data-freshness)[HTTP HeadersKey-value metadata fields sent with HTTP requests and responses that communicate authentication, content type, caching, and other directives.](https://alterlab.io/glossary/http-headers)

## Extract Cache Busting data from any website

AlterLab returns clean, structured data from any public URL — no scraper infrastructure needed. Start free, no credit card required.

[View API docs](https://alterlab.io/docs/api/rest)

[Back to Glossary](https://alterlab.io/glossary)