(I was inspired to inquire about this after learning about the recent changes made to Google Chrome regarding how it handles emojis)
After briefly searching through Discourse Meta, was unable to find out if the emojis built into Discourse are SVGs or not, but if they aren’t, then I see no reason why they shouldn’t be.
Could somebody please set this straight for me? Thanks in advance! 
No, they are PNGs.
We support multiple sets and not all sets are available as SVGs.
Are the PNG sets able to be converted to SVGs?
Sorry, this isn’t my area of expertise.
There are some free online PNG-to-SVG file converters as well as downloadable software for off-line converting. Some only handle one file at a time, but there may be some that will handle sets of files. I haven’t checked them out myself, but if you run a simple search using can a png file be converted to svg you can check out the different offerings yourself. Experiment with different converters as some may give better results than others.
Oh, yes. I’m aware that those exist, but I’m just suggesting that the emojis in Discourse core should be SVGs by default.
Why? When we are talking about emojis, SVG gives zero real-world benefits, but gives a lot of issues because without manual converting such option should change to PNG anyway.
But sure — it could be an option, but default?
What do you mean? It makes them significantly more crisp and detailed, regardless of your device’s size and the scale of the webpage.
With emojis? No it does not.
Again, what do you mean? As I’ve already explained above, it absolutely does.
Will unlikely be any crisper, we include higher res emojis than the ones rendered, browsers these days do a fine job downscaling images
If we were to show emojis that are 800px by 800px, sure svg would likely be better
Feel free to post screenshots showing how the current downscaling is causing visual issues
Absolutely not. You are counting milliseconds that have only lab meaning, nothing else.
Where do you need scalable emojies? What is that user case IRL?
With all due respect, what are you even talking about?
A real user can’t see that time difference. And lag of network, devices etc. are way bigger than loading/serving time savings what SVG emojies gives. Lab tests shows soemthing like 20 ms benefits that are totatally theoretical.
And the most important thing: Google just doesn’t care.
Sure, maybe you can’t see the time difference, but what about other users?
What lab test? Do you have a link to it?
That doesn’t explain this though.
No one can. Do you understand size of an emoji?Just redirecting to subdomain takes longer. Even loading up a topic without a single emoji takes longer.
Do you know how long a eye blink takes?
Again. It can be an option if you or anybody else can find SVG-only emoji library. But it can’t be opt-out. And the work to achieve speed effort, that not makes any forum faster — there is no point.
If you really don’t know how to measure speed of a site or do stress tests it is not my job to teach you. Do some googling. But if you don’t know those basics it tells why you are so sure SVG emojies make a forum faster 
Try not to get off track here, making emoji SVGs is not a major priority for us until we have some real-world examples in Discourse that show us there’s a problem. We have no existing issues with “crispiness.”
Debating which method is technically best isn’t going to get much traction here (so I recommend stopping). It has to be significant enough for us to prioritize it over other work.
Yeah, agreed. Sorry that this topic is going nowhere. Feel free to lock it.