I wonder if we should do this for desktop only, basically assuming that "desktop" means faster unmetered network. @ori, do we have a reliable way to detect when its ok to download extra data, or when it should be "on demand"?

@ori: Is there a reliable way to detect when its ok to download extra data, or when it should be "on demand"?
(Repeating @Yurik's question here.)

In T124254#1952553, @Yurik wrote:

do we have a reliable way to detect when its ok to download extra data, or when it should be "on demand"?

No, not right now and unlikely for the foreseeable future. I would recommend against loading the client-side rendering by default on page views with graphs. However we can lazy-load it based on user interaction. The "play" button is a good start and seems to work well. This could be extended and integrated further to feel more seamless for the user. I imagine the current play button may feel like a boundary that makes interaction less likely, indeed.

PS: It seems mode=interactive doesn't work on https://www.mediawiki.org/wiki/Extension:Graph/SampleGraph?

It is now four years later and bandwidths have increased. How much of an issue is the overhead these days? I am sorry that I do not know how to measure this myself. I would really like the graphs on Wikipedia to look nicer and more similar to the rest of the Web.

If we do not want to have client-rendered graphs throughout, would it then perhaps be possible to publish a PNG file that looks as nice as the SVG file in the preview? Looking here https://en.wikipedia.org/wiki/Template_talk:Graph:Chart for instance, the graphs are noticeably blurry, in particular al the numbers on the axes are blurred. But in preview mode, they look fine! I do no understand why the final PNG should look so much worse; just taking a screenshot and publishing that would give much nicer results.

Another option could be to let users choose what kind of graphs they want to see in their general settings.

@KarlFrei actually that might be happening later this year: T236892 mostly because the graphoid service is lacking maintainers.

The current graph rendering looks blurry on most displays as most displays are now "HiDPI" displays (more dots per inch, eg. 2x2 dots per virtual pixel is common).

For SVG PNG and JPEG images from Commons, MediaWiki renders its thumbnails at 2 dppx (2x), which is why those look sharp. If Graphoid were configured to also render at 2x, they would look sharp again as well. This isn't due to whether it renders a PNG or with JS.

Apparently this is now resolved.

Just curious, which patch fixed this?

All graphs are rendered client side now, since graphoid was undeployed (via a series of patches over a long-ish time). Graphoid not existing is not ideal for a number of reasons, but it does indeed "solve" this problem :)