There are 1-page websites (mostly personal websites, sometimes business too) that do decently in search results, especially where the focus is local SEO only. However, 1-page sites aren’t ideal to get the most of SEO opportunities.
Small and medium business websites could be 10 to a few 100 pages based on their services/products and keyword opportunities.
Institution, corporate, news and government websites could have from thousand to millions of web pages.
Rather than looking for the number of pages an average website should have, one should ask how many pages would be ideal to serve their needs?
The number of pages that a website must have for good SEO is something that cannot be simply standardized. It largely depends on the nature of the business and keyword opportunities that can yield quality traffic and conversions. If you are a local business with only up to 3 relevant and not very competitive keywords that could bring new customers, your business can compete in search results with just a 1-page website.
However, if your business offers, let us say 10 services, and operates nationally in a competitive niche, then a 1-page website may not be the best way to go about dominating SEO rankings in your country.
It is advised that websites have at least have 1 dedicated page for each of its product/service/keywords.
Let us assume that a business has 5 key services and 15 unique keywords with good search volumes that it would like to get found for.
In such a case the website should at least have around 15 pages with high-quality content that helps the website to rank well in search engines and get more traffic for each of those keywords.
Before you start working with a web design company, it is important that you know all keyword opportunities for your business.
Without this information, your website could easily miss on acquiring traffic.
Comprehensive keyword research also enables you to build a good website architecture.
A lot of pages alone might not get you the results you need
Simply having a lot of pages on the website may not necessarily fetch great SEO results.
Without highly sophisticated, original content, and managed SEO services for increasing website authority, your online presence might as well be futile.
Websites like Wikipedia perform well in search results not only because of the number of pages it has but because of its highest quality content and its online authority or reputation as a credible website.
Having a lot of pages on your website that target the right keywords does not guarantee SEO performance.
But, it is the first step that you should take to achieve great SEO results as you move forward with SEO and content marketing services.
Having the highest quality content that is original, engaging and optimized for SEO is what is most important.