Thousands of Reddit communities have gone dark in a two-day protest over proposed API pricing changes which could see third-party app developers priced out of the platform.

Reddit, the popular news and discussion site, announced its proposed pricing changes around two months ago when it revealed some third-party apps would have to start paying for access to its application programming interface (API), beginning 1 July.

The subsequent weeks saw bubbling tensions among community moderators and users alike – many of whom pointed out an inherent threat to popular third-party apps focusing on accessibility and research – and in early June, countless subreddit announced they would be banding together in a coordinated protest.

"Reddit announced they were raising the price to make calls to their API from being free to a level that will kill every third-party app on Reddit," read a popularly cross-shared post on Reddit.

"This isn't only a problem on the user level: many subreddit moderators depend on tools only available outside the official app to keep their communities on-topic and spam-free.

"On June 12th, many subreddits will be going dark to protest this policy."

The backlash effort went ahead on the proposed 12 June date, with more than 7700 subreddits (housing a collective subscriber count of over 2.84 billion) currently set to private, according to third-party app Reddark.

While private, subreddits are made inaccessible to the wider public, and users are met with a lock-out screen displaying only a scant message from community moderators.

Users found similar messages waiting for them on various subreddits. Photo: supplied

"/r/Funny has shut down as part of the coordinated protest against Reddit's exorbitant new API pricing. Do not message to request access," reads a notice on the landing page of /r/Funny, a Reddit forum with over 40 million subscribers.

"This community has shut down and will not grant access requests during the protest.”

Other gigantic subreddits joining the cause include r/gaming, r/Music and r/science – the latter of which cited a negative impact on "third-party tools, accessibility and moderation" as a result of Reddit's proposed API changes.

More obscure subreddits are pitching in as well, with smaller communities such as r/StarTrekDiscovery, r/ColecoVision and r/SteamedHams currently left dark for their thousands of subscribers.

Multiple third-party app creators have announced outright closure amid the backlash, including Apollo developer Christian Selig, who said at its current rate of 7 billion API requests per month, he would need to pay $2.5 million (US$1.7 million) for access to Reddit's API, or $29.6 million (US$20 million) a year.

"I don't see how this pricing is anything based in reality or remotely reasonable," said Selig.

"I hope it goes without saying that I don't have that kind of money or would even know how to charge it to a credit card."

In spite of being Reddit's most popular third-party app, Selig announced Apollo will shut down due to the new API fees on 30 June.

A Reddit employee challenged the widespread backlash, arguing the proposed API changes may be affordable if third-party apps are developed efficiently regarding the amount of API calls they make.

“Our pricing is $0.24 per 1,000 API calls, which equates to <$1.00 per user monthly for a reasonably-operated app,” they said.

“Apollo as an app is less efficient than its peers and at times has been excessive – probably because it has been free to be so.”

Furthermore, Reddit co-founder and CEO Steve Huffman stuck to the changes when he suggested updates to API pricing were a necessity in order for Reddit to remain viable.

"Reddit needs to be a self-sustaining business, and to do that, we can no longer subsidise commercial entities that require large-scale data use,” said Huffman.

Reddit has also declared intentions to bar third parties from accessing explicit content via the API, and third-party app developers have raised further concerns over their ability to show ads.

"Apps can also no longer show ads which was a primary source of revenue. So not only do they have to pay exorbitant fees, they can't even mitigate those fees with ads," read an open letter on Reddit.

The solidarity effort is planned to last 48 hours in total, however, some subreddits have declared longer or even indefinite hiatuses under Reddit's coming changes.

Notably, the r/blind subreddit said should the API changes take effect, the page may shut down permanently – citing lacklustre accessibility options for blind users in Reddit's default app.

A popularly reshared post describing the protest said should things reach 14 June with no sign of Reddit "choosing to fix what they've broken", protestors would look into taking further action.

"The two-day blackout isn't the goal, and it isn't the end," read the post.