Algorithm Changelog (ongoing)

a bit later today we’ll be pushing out a beta update on iOS and Android that includes a new explore channel called Popular 2. this is an experimental channel where we test new algorithms, some of which will eventually be moved into Popular Now

in order to keep things transparent we will update this thread whenever we make changes to the algorithm. while we will provide enough detail to make it easy to understand the spirit of the changes, we will likely stray from providing full details (e.g. down-to-the-number) so that it is more difficult to game these algorithms if and when they’re promoted into Popular Now in the future

on a somewhat related note: a reminder that the explore tab isn’t finished. we will continue to look at the balance between popularity/discovery and consistency/reach as we add new features and channels to explore


initial version:

  • p2 looks at posts over the last 24 hours and ranks them on a score system, with likes counting towards a post’s score and a post’s age counting against it
  • the intent is that new posts with traction will rise to the top as older posts that previously topped the timeline drop off
  • the p2 timeline is refreshed every 5 minutes

some tweaks were made today:

  • now includes posts from the last 48 hours
  • the scoring curve has been adjusted to significantly favor newer posts with traction

a note on how auto moderation works:


we’ve decided to temporarily disable the functionality that excludes automodded content that hasn’t been reviewed from public feeds. we’ll turn this functionality back on once our review time is under 30 minutes. we’ll post another update once this change has been deployed


we’re currently testing the change from above and plan to deploy it in the next few hours

update: this change has been deployed


we’re planning on pushing a change that will insert a post you’ve rebyted into your home feed if it wasn’t there already. we’ll post another update once this change has been deployed


this change has been deployed! note that there is a minor bug that happens occasionally when unrebyting posts from people you don’t follow. we are aware of this bug and will fix it in a future update


we’ll be pushing out a beta update on iOS and Android that includes a new explore channel called Your Mix. this is an experimental channel that tests a new algorithm candidate for the explore section

  • Your Mix looks at posts over the last 60 days and assigns them a score that is similar to p2
  • unlike p2, the score only affects the likelihood that a post will be selected for Your Mix, but the list is not sorted by score
  • in other words, this channel is semi-random and contains a mix of popular posts and “deep cuts” that have shown some traction
  • Your Mix refreshes every time you access it and is different for every user
  • in the future you will be able to be able to personalize Your Mix by subscribing to channels/categories in Explore (e.g. comedy, sports, animals) which it will then pull from

with the channels update, the following changes have been made:

  • popular now is now using the popular 2 algorithm
  • popular 2 has been retired, but may return in the future as we test changes to the popularity algorithm
  • the trending algorithms in channels are the same as the new popular now algorithm, but are for that channel only
  • “global megafeed” has been renamed to “latest”

the channels update is rolling out to iOS testers now and will come to android next week


there is a bug with trending algorithms in channels that cause them to be weighted differently than the new popular now (formerly popular 2). we’re working on fixing this and will post another update when it’s deployed

thank you for bringing this to our attention :slight_smile:


this should be fixed now (might take a few minutes for feeds to rebuild)


in preparation for a larger audience, we’ll be pushing an update to Popular Now that decays posts more quickly. the effects we expect to see are:

  • Popular Now changing more often
  • the “ideal time to post” being less important
  • the # of likes for items at the top of the list will be lower

we’ll post again when this change has been deployed


this has been deployed. we will look at this for a little bit and possibly make changes to increase or decrease the decay. we’ll let you know what we’re thinking once we’ve had a bit of time with it


we’re still evaluating the decay change, but we will be working on an additional change that limits the number of times a user can appear on Popular Now at any given time to 1. in the case that there are multiple potential posts by one user, the highest weighted post (e.g. the one that would be highest on the list) will be the one that appears


we’ve deployed the change that limits simultaneous Popular Now posts by a user to 1

here’s a clarification scenario on how this works:

  • you make a post and it starts trending so it shows up on popular now
  • later in the day you make another post
  • at this moment, your first post is still the one that shows up because it still has a fairly high weight and the second post is brand new
  • your second post starts picking up in popularity through followers, channels, etc
  • at the same time your first post is decaying because it’s getting older
  • eventually your second post “overtakes” your first post
  • your second post is now the post that shows up in popular now

Your Mix — which is currently an experimental feed — will be receiving a large upgrade a little bit after launch. this feed will utilize machine learning and act as a personalized recommendation feed designed specifically for you. you’ll also be able to subscribe directly to channels to more notably incorporate them into Your Mix. we’ll share more details about this second iteration of the feed once it’s ready to test

once we’re comfortable with the new iteration of Your Mix, we’ll be promoting it to a more prominent position in the Explore tab. we’re still working on UI treatments but will share more information on this as well as they come together


while we work on the Your Mix improvements above, we’ve decided to temporarily bring back Popular 2, with new rules. here’s how it will work this time around:

  • the top 1,000 current Popular Now posts will be randomly shuffled in this feed
  • the feed will be different for everyone and shuffled every time you load it

we’re going to try to deploy this tomorrow and will post another update when it’s done


Popular 2 has been deployed!