There's no single best time to post on Reddit. The real answer is per subreddit, because every community has its own crowd and its own clock. The chart above shows you when a specific subreddit's conversation starts. If you're replying to someone else's post (not creating your own), timing matters less than replying while it's fresh.
How to use it
- Type a subreddit into the box above, with or without the r/. You don't need an account and nothing you enter is stored.
- Read the two charts. The 24-bar chart is hourly activity, shifted to your own timezone, so "9 AM" on that chart means 9 AM where you are, whatever that is in the subreddit's own time. The 7-bar chart is by weekday, and it stays in UTC (more on why below).
- Check the three hours named above the chart. Those are the subreddit's busiest three hours in the sample, already converted to your clock. If you're going to pick a time to post, start there.
Both charts answer the same question from two angles: when does this subreddit wake up, and which weekday carries the most of its conversation. Neither one tells you what to say. For that, the subreddit's actual rules matter more than its clock, which is what the subreddit rules checker is for.
A quick worked example. Say you check a subreddit and the top three hours come back as 9 AM, 10 AM and 2 PM in your timezone, with Tuesday and Wednesday busiest in UTC. This subreddit's conversation clusters around late morning on weekdays, so a post or reply in that window reaches more readers than one posted at 3 AM on a Sunday. Read the chart as a rough window, not a single magic minute.
What the bars measure
Each bar counts posts that started in that hour, plus the comments those posts went on to collect. Comments matter because a post's timestamp only tells you when someone hit submit. The comments show when other readers arrived and read it, which is closer to what "best time" should mean if the goal is visibility.
The count comes from a sample of the subreddit's recent posts, not the subreddit's entire history. The tool shows you the sample size and how many days it covers, right under the chart, so you're not taking the bars on faith. A subreddit with a thin sample, a few hundred posts over a couple of weeks, is going to look much noisier than one with a large, steady posting volume, and the tool doesn't hide that difference from you.
There are roughly a thousand subreddits that are pre-cached. Checking one is instant and free because the counting already happened. A subreddit that's never been sampled requires a fresh fetch from the data provider the first time someone asks about it. Then it gets counted and cached, so the next person gets the instant answer. You pay that first-fetch cost only once per community.
This is the same shape of tradeoff across all the free tools on this site. A community that's been read once answers for free from then on. A new community gets read once and then joins the instant answers pile. The tool can stay free because the expensive part, fetching a subreddit's history from a data provider, happens once per community, not once per visitor.
Posting versus replying
If you're posting your own thread, the hour is worth thinking about. If you're a founder replying to someone else's post, hoping they see your answer, the calculation is different. What matters most isn't the hour on the clock. It's how old the thread already is.
A thread that's six hours old has mostly finished collecting the readers it's going to collect. A thread that's twenty minutes old is still being read by the people who are going to read it. Reply to the fresh thread and a stranger might see your answer. Reply to the stale one and you're talking to an empty room, no matter how good the hour was.
This is why "reply early" matters more than picking the absolutely perfect hour. A mediocre hour on a fresh thread outperforms a great hour on a stale one. If you're going to optimize just one variable, optimize thread age, not clock time.
Here's why this works. Reddit open-sourced its ranking code years ago (the archive is on GitHub). The "hot" sort scored posts based on votes, then steadily discounted that score as the post aged, on roughly a half-day scale. Reddit hasn't confirmed its current ranking works the same way, but longtime users notice the same pattern: threads decay fast. Once visibility drops, votes and comments barely move the needle. A comment on a thread that's fallen off the front page is invisible to most readers who would've seen it on day one.
That's why Radar's inbox refreshes every six hours and holds the 30 best-fit threads from the last 14 days, not everything ever posted about your product. A thread from three weeks ago isn't worth a reply anymore, even if it was perfect on day one. For more on what makes a thread worth replying to, see how Radar decides a thread is worth a reply.
What the public studies say
Before I wrote this, I went through the studies that usually get cited for best time to post. Sprout Social's 2026 report covers Facebook, Instagram, LinkedIn, Pinterest, TikTok and X. Buffer's 2026 guide adds YouTube and Threads. Hootsuite's research, which analyzed over a million posts, covers Instagram, Facebook, X, LinkedIn, TikTok, Threads and Pinterest.
None of the three cover Reddit. It's simply not in their platform lists.
This makes sense once you understand what those studies are measuring. They're built for brands with one account and one audience, where a single global best hour makes sense. Reddit doesn't work that way. There's no single Reddit audience: r/startups, r/AskReddit, and niche communities like a board game subreddit each have their own timezone, rhythm, and preferences. A site-wide average would erase the value: each subreddit's timing is unique. This tool asks for a subreddit name instead of publishing one global chart because that uniqueness is the entire point.
Search online and you'll find plenty of blog posts from scheduling tools that claim a specific best hour for "Reddit," usually something like weekday mornings Eastern Time. Most don't show their sample size or date range, and some come from companies selling Reddit scheduling and posting tools, which have reason to oversell timing as the most critical factor. I'd rather point you at a chart built from the specific subreddit you're asking about, with the sample size shown, than repeat a number I can't verify.
Timezones and why UTC shows up
Reddit's biggest subreddits skew toward a US audience, though the mix varies by community. The hour chart above converts everything to your own timezone, so if you're in Lisbon and the subreddit's chattiest hour is 9 AM Eastern, the bar you see is already labeled for your afternoon. You shouldn't have to do that math yourself.
The weekday chart is different. It stays in UTC on purpose. A day boundary (midnight) falls at a different local hour depending on your timezone, so if the weekday chart shifted to your clock, "Tuesday" could shift an hour or two from Monday or Wednesday depending on where you're sitting. Keep it in UTC and the day boundaries stay fixed for everyone looking at the same subreddit, even if specific hours still shift on the other chart.
Reading a chart for a small subreddit
A subreddit with a handful of posts a day is going to give you a jumpy chart. One unusually busy Tuesday in the sample window can make Tuesday look like the community's clear peak day, when really it was one post that did numbers. That's noise, not a pattern, and the sample size shown under the chart is your warning sign: the smaller it is, the less you should read into which bar is tallest.
If the bars look mostly flat and close in height, this subreddit doesn't have a strong best hour. Any reasonable time works. Don't read patterns that aren't there. In a small, low-traffic community, the subreddit's actual rules and the specific thread you're replying to matter a lot more than which hour you show up. Check what's allowed before you post, and if you already have a draft ready, run it through the reply checker before you paste it in.
People often want to find a pattern in noise. A jumpy chart with one tall bar looks like a finding, but it's usually just one post that blew up, skewing one hour and one day. Small communities are noisier than large ones. That's the nature of the data, not a chart problem. The fix is knowing when to stop reading the chart and trust your own judgment.
A simple routine
Here's the order I'd do this in when approaching a subreddit I hadn't posted in before:
- Check the rules first. A perfect hour doesn't matter in a subreddit that bans your kind of post outright. Read the actual rule, not a vibe, before you write anything.
- Check the hour. Use the chart above, pick one of the three named hours if your schedule allows it, and don't stress if it doesn't. This is the smallest lever of the four.
- Reply early. Find fresh threads and answer them within hours, not days. The thread's age does more work than the clock does, for the reasons above.
- One pitch per subreddit, then a cooldown. Don't post your product in every thread you find in the same community. Answer to help, mention your product once if the rules and the moment call for it, then leave that subreddit alone for a while before you do it again. Communities notice repeat pitchers faster than they notice good timing, and a subreddit that starts recognizing your username as "the person who always mentions their tool" stops reading your comments in good faith.
None of these steps is hard on its own. Doing all four together, on the right thread before it goes stale, is the real work. Most people skip this part. A founder who does all four usually gets a reply that reads like an answer, not an ad, regardless of the hour.
If you'd rather have this whole routine run for you, including finding the threads and drafting the reply, that's what Radar does. Scan my site free and see the communities where your product fits before you spend an evening guessing.
FAQ
Does posting at the "best hour" guarantee more upvotes?
No. It raises the odds that people are around to see the post when it goes up, which is a precondition for engagement, not a guarantee of it. What people do with your post once they see it still depends on the post itself, and on whether the subreddit's rules and mood are a fit for what you're posting. Timing gets you an audience. It doesn't write the post for you.
Why does the weekday chart use UTC instead of my timezone?
Because a day boundary shifts with your offset. If the weekday chart followed your local time, part of one UTC day could get relabeled into the next or previous day depending on where you are, which would make the weekday comparison unreliable. The hour chart still shifts to your clock, since an hour doesn't have that boundary problem.
Is this the same data Radar uses for its paid inbox?
It's built the same way: a histogram of recent posts and their comments for a subreddit, sampled and cached. The paid product goes further. It finds threads worth replying to, scores them for fit against your product, and drafts a reply, none of which this free chart does on its own. The inbox also refreshes on its own schedule, holding the 30 best-fit threads from the last 14 days rather than asking you to go looking.
My subreddit shows a small sample size. Should I trust the chart?
Trust it less than you would a chart built from thousands of posts. A small sample can make one busy day look like a pattern. Use it as a rough starting point, not a rule, and lean more on the subreddit's rules and the age of the specific thread you're replying to.
Does this tool tell me what to actually write in my reply?
No. It only tells you when a subreddit tends to be active. For whether your draft reads like a person, discloses that you built the product where it should, and doesn't break a self-promotion rule, use the reply checker.
I don't know which subreddits fit my product yet. Where do I start?
Start with find my subreddits. Paste your site's URL and it runs Radar's actual scan: reads your site, finds the communities that fit, reads their rules, and shows you live threads with a reply ready to copy. No card required.