Google’s &num= Parameter Removal: Impact on SERP & Moz Pro

Google's decision to remove the long-standing `&num=` parameter from its search results URLs marks a significant shift for the SEO industry, particularly impacting SERP scraping and rank tracking technologies like Moz Pro. Previously, the `&num=` parameter allowed users and tools to specify the number of organic results displayed per page, with `&num=100` being a common method for efficient data collection, reducing the need for multiple pagination requests.

This removal has an industry-wide effect on SERP scraping costs. Tools and services that relied on `&num=100` to collect up to 100 results in a single request must now adapt. To acquire 100 results, scrapers must make ten separate requests, each yielding 10 results, or navigate through subsequent paginated pages. This necessitates increased resource allocation, including more IP addresses, proxies, bandwidth, and processing time, thereby escalating operational costs for data providers.

For Moz Pro, a key technology in the SEO toolkit, this change directly impacts its Rank Tracker feature. Historically, Moz Pro leveraged the `&num=100` parameter to identify and track website rankings beyond the crucial top 10 positions, up to position 100. With the parameter's deprecation, Moz Pro has adjusted its technical specifications: it now exclusively scrapes the first 10 organic results for each tracked keyword. Consequently, Moz Pro will no longer reliably detect or report rankings for URLs appearing from position 11 onwards.

The primary benefit of this adaptation for Moz Pro users is continued accuracy for the most critical top 10 rankings. However, the target audience, comprising SEO professionals and marketers, will observe a significant change in their rank tracking data. Keywords where their site previously ranked between positions 11 and 100 will now show as “N/A” or reflect a drop in reported ranking, even if the actual position hasn't changed. This shift underscores the increasing importance of achieving top-10 visibility and requires users to recalibrate their interpretation of rank tracking data within Moz Pro.

(Source: https://moz.com/blog/num-100-and-changing-serp-lengths-in-moz-pro)