Posted by caminanteblanco 19 hours ago
* The charts are never blurry
* The text in the chart is selectable and searchable
* The file size could be small compared to PNGs
* The charts can use a font set by a stylesheet
* The charts can have a builtin dark mode (not demonstrated on my blog)
Additionally as the OP shown, the text in SVG is indexed by google, but comes up in the image sections [1].
The downside was hours of fiddling with system fonts and webfonts and font settings in matplotlib. Also the sizing of the text in the chart and how it is displayed in your page is tightly coupled and requires some forethought.
[0] https://aleyan.com/blog/2025-llm-assistant-census
[1] https://www.google.com/search?q=%22slabiciunea+lui+Nicu+fore...
[1] https://www.masswerk.at/6502/6502_instruction_set.html#stack
- smaller file sizes
- dark mode
- readable text
- selectable text
(For web apps, I feel I can soften a bit, as you’re more likely to be able to rely on styles. But I would still suggest having appropriate width/height attributes, even if you promptly override them by CSS.)
It’s way undervalued and rarely gets updates.
I wrote a small graphing library for mine [1], but it has limitations.
[1] https://coffeespace.org.uk/projects/sound-source-delta.html
Also of interest for me would be whether SVG description markup gets picked up in the index.
To complete the search of possibilities, having the SVG generated by Javascript on page load would be of interest, for example, with some JSON object of data that then gets parsed to plot some SVG images.
Your SVG graphs are very neat and nobody caring is a feature not a bug. If they were blurry PNGs then people might notice but nobody notices 'perfection', just defects.
I noticed you were using 'NASA numbers' in your SVGs. Six decimal places for each point on a path is a level of precision that you can cut down with SVGOMG or using the export features from Inkscape. I like to go for integers when possible in SVG.
The thing with SVG is that the levels of optimisation go on forever. For example, I would set the viewbox coordinates so that (0, 0) is where the graph starts. Nobody would ever notice or care about that, but it would be something I would have to do.
What is the motivation for viewbox coordinates being at (0,0)? I have been thinking about setting chart gutters so that the graph is left aligned with the text, but this seems like an orthogonal issue.
Rather than use MatLab to create your bar charts, you could do something like this.
Here I am assuming you don't want standalone images that others can steal but you do want maximal SVG coolness.
Move the origin with viewBox voodoo witchcraft to 0,0.
Add a stylesheet in your HTML just for your SVG wizardry.
Create some CSS properties scoped to SVG for your colours, for example svg { --claude-code: red; --cursor: orange; --github-copilot: yellow; } and so on.
Put them in the stylesheet, and add some styles, for example claude-code line { stroke: var(--claude-code); } and so on.
Rather than use paths in groups with clip paths and whatnot, just use a series of lines, made nice and fat. Lines have two points, and, since the viewBox is zeroed out to the origin, you only need to specify the y2 value, with y1, x1 and x2 taking the defaults of zero. The y2 value could be whatever suits, the actual value divided by 1000, 10000 or something.
Put each line in a group with the group having a class, for example claude-code.
Add the label to the group with its own transform to rotate the text 45 degrees.
Add a transform to the group to move the fat line and its label along the y axis using a translate.
Rinse and repeat for all entries on the graph.
Now do some labels for the other axis.
As for the title of the graph, move that out of the SVG file. Put the SVG file in a figure element and put the title in a figcaption element. Add CSS for the figcaptions.
With SVG in HTML there is no need to do xlink and version things, just keep it simple, with just the viewBox and no width/height. Scale your figures in CSS with the SVG set to fill the space of the figure, so we are going full width.
You can also use some title elements for mouseovers, so, hover over a bar and you get the actual data number.
Why do it this way?
Say you don't like the colours or you want to implement dark mode. You can do the usual prefers media query stuff and set your colours accordingly, for all the graphs, so they are all consistent.
Same goes with the fonts, you want all that in the stylesheet rather than baked into every SVG, so you can update them all with one master change.
As for the last graph with lots of squares, those squares are 'rect' not path, for maximum readability. The rectangles can be put in a defs container as symbols, so you have veryLightBlueSquare, lightBlueSquare, BlueSquare and so on. Then, with your text you can put each value in a group that contains a text node and a use tag to pull through the relevant colour square.
Though it'd discourage anyone to run off with this idea.. b/c SVGs are unfortunately kinda janky
My top 3 issues are:
- not even overly complicated SVGs, especially with text, will render notably different in different browsers (and renderers like Batik/Inkscape/SalamanderSVG/etc). I have no idea why.. PDFs don't have this issue. While I haven't tried, but I don't think PDFs are as easy to generate programmatically as SVGs
- SVGs have completely broken linking. You can embed an <svg> inside another <svg> to reuse an element - but for some reason it's limited to a link depth of 1! So you can't link an <svg> that links an <svg>. So SVG aren't safely composable - which drives me nuts.. (ex: making a large display panel in SVG that has subcharts)
- Maybe minor.. but tooltips in SVG (which are super handy.. for instance in plots to display additional info about a data point) don't work when the SVG is in an HTML page. They seem to only work when you open SVG in a separate tab.
More abstractly they just have very weird perf issues. Some mildly complex SVGs take GBs of RAM and 1> min to render. But it's unclear which parts are performance sinks.
If you aren't careful they can be used for XSS and all kinds of nasty stuff.
They are also super useful in general though despite that.
The only thing that separates it from html and css is that html and css biases towards website styled stuff. HTML is designed for text boxes and that kind of stuff while svgs bias more towards a neutral drawing medium: shapes and vectors.
So because it’s more neutral you can even make a html engine from svg if you so wanted.
They do get indexed by Google, and we take some extra steps to ensure usability.
A while back I used a giant interactive SVG as the UI for a site I was prototyping, albeit wrapped in a normal HTML page. It was easy to set up and worked reasonably well, but I found that in Firefox performance started to degrade beyond a few thousand elements and so converted everything (except some accessibility features) to use a canvas instead. (The core of the old version is still deployed here if you want to see how far you can push it: https://freeclimbs.org/wall/demo/edit-set )