The website, one of several projects run by Wales, is advert-free and relies on donations of at least $10m (£6.2m) a year to keep it running.
More than 340m people use Wikipedia every month – almost a third of the internet-connected world. The site is administered through Wales’ charity Wikimedia.
The Christmas appeal, which has been repeated every year for the last six years, drew in $430,000 in its first 24 hours – the largest amount ever taken in that time period.
In total, Wales is asking for $7.2m.
In an open letter on Wikipedia’s website Wales said: “Wikipedia isn’t a commercial website. It’s a community creation, entirely written and funded by people like you.
“Wikipedia is about the power of people like us to do extraordinary things. People like us write Wikipedia, one word at a time. People like us fund it. It’s proof of our collective potential to change the world.
“We need to protect the space where this important work happens. We need to protect Wikipedia. We want to keep it free of charge and free of advertising.”
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