# Rate Limiting

> Canonical HTML version: https://rocketvalidator.com/docs/rate-limits
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

When you submit a site for validation, Rocket Validator will scrape the site to search for internal web pages, and check each of them for HTML and Accessibility conformance.

This means that your site will receive requests from our different subsystems while it's being validated:

* **Crawler**. Your web pages will be visited to discover internal links to other pages.
* **Engines**. Each page is fetched again by the checking engines: W3C Validator for HTML, and Axe Core and AccessLint Core for accessibility.
* **Screenshots**. A screenshot of each page is taken when the option is enabled.

So validating a site with 1,000 web pages adds up to several thousand requests in total.

## Avoiding server overload

To avoid overloading your server, we carefully rate limit the requests to ensure they don't happen all at once, but a buffered rate. The following limits are applied:

- Trial accounts have a limit of 3 requests per second.
- All paid plans have a limit of 10 requests per second.

On top of that we impose a rate limit on each host, to ensure that even if you're running simultaneously several site validations on the same host, a global limit is applied.

## How to reduce the number of requests

To avoid making too many requests to your servers we recommend:

* **Setting a low rate limit**. The default rate limit is 3 reqs/second, but you can set it as low as 1 req/second.
* **Using an XML or TXT sitemap**. You can provide an XML or TXT sitemap specifying the exact URLs to validate. This way the scraper can avoid crawling your internal pages in search for links. <a href="https://rocketvalidator.com/docs/performance-tips#using-an-xml-sitemap">Read more about XML or TXT sitemaps</a>.
* **Skipping A11Y validation**. By default, reports include A11Y validation on top of HTML validation. You may consider skipping A11Y validation and focus on fixing the HTML issues first.