HTML document

What we check

We load the HTML of the home page, that is the first file that a browser fetches, and measure:

• Loading time from the start of the request to the last byte of the HTML, including all redirects, DNS lookup, connection setup, TLS handshake, server response and download. Images, fonts and scripts do not count. Over 2 seconds there is a warning.
• Size of the HTML. Over 200 KB there is a note, over 500 KB a warning, over 2 MB a serious defect, because Google cuts the HTML off there. In the report you also see how much of it was actually transferred, that is after compression.
• Redirects up to the home page. From two there is a note.

Why it matters

The HTML is the foundation of every page. Only once the browser has loaded it does it know which images, fonts and stylesheets it needs besides. Everything that delays the HTML delays the whole page.

Redirects are often invisible: anyone who types example.ch may first be redirected to https://example.ch, then to https://www.example.ch and finally to https://www.example.ch/de/. Each step is a request of its own, on a smartphone 0.1 to 0.5 seconds each.

Large HTML takes longer to transfer and to process. A healthy HTML file for a home page is usually between 30 and 150 KB. Values above that arise when images are embedded directly in the HTML, page builders write extensive style information into every page, or shop and booking systems deliver large amounts of data along with it.

From about 2 MB a second problem is added: Googlebot reads only the first 2 MB of an HTML file. Everything after that, such as texts, links or structured data at the end of the page, does not exist for Google.

How to fix it

Shorten redirects

• Redirect directly to the final address, not in several steps. The redirect from http://example.ch should lead to https://www.example.ch/ in one step.
• In ads, newsletters, on business cards and in social media profiles, link the final address.
• If the home page redirects to a language version such as /de/, check whether the German page cannot appear directly at /.

Make the HTML smaller

• Load images as files of their own, not embedded as a data: address.
• Move large <style> and <script> blocks into files of their own. The browser can cache these.
• With page builders, options such as "Write CSS to external file" help (Elementor: "CSS Print Method: External File").
• Check whether the home page loads elements that are not visible at all, such as hidden pop-ups, mega menus with hundreds of links or complete product lists.

Faster server response

If the HTML is small but still slow, the server is the cause. More on this in the article on TTFB (Time to First Byte).

How to check it yourself

Open the developer tools (F12), "Network" tab, activate "Preserve log" and reload the page. The first lines show the redirects (status 301 or 302) and the HTML document with its size and loading time.

Frequently asked questions

Why is the HTML so large?

Usually it contains things that belong in files of their own: embedded images (as long character strings), large blocks of styles and scripts, or data that a page builder or an app delivers along with it.

How many redirects are fine?

One is normal, for example from http to https. From two we give a note, because each further one costs an additional request, which is often noticeable on a smartphone.