Publishing Your Reference Tables as Images

Your reference pages publish real HTML tables, which is exactly right: a search engine can read them, quote them, and lift them into an answer. A picture of a table can do none of that, so the tables stay where they are and this adds something beside them.

What it adds is for image search, which is a separate index with its own visitors. People looking for a lookup table go there deliberately, because what they want is something to look at. Until you make these, the only picture those pages offer image search is your logo.

Making them

Open Media in the admin and scroll to Reference tables as images. Press Render what is missing or out of date. Each table takes a few seconds, which is why it is a button and not part of a page load.

Each image is drawn from the rows on its own page, so it cannot end up showing something different from the table printed above it. A fingerprint of those rows is stored with the file, so if you later edit a table the admin shows that image as out of date rather than leaving a stale picture in place.

What you get

Once an image exists, its reference page gains a "Save or share this table" section with a download link, the image is declared in the page's structured data under the same CC BY 4.0 licence as the table, it becomes that page's social preview image, and your sitemap names it so search engines are told it exists.

Requirements and limits

Rendering needs headless Chrome, so this works on a VPS and not on shared hosting. Where Chrome is missing nothing is written and your pages look exactly as they do now.

A very tall table, such as a full 99 row list, is left as a larger PNG rather than being optimised, because optimising an image that size needs more memory than a typical PHP limit allows. That is deliberate: a larger file that works beats a fatal error halfway through.