Look at the last post you made. Count the tags. If you're like most Tumblr creators, there are a dozen or more, typed from memory in roughly the same order you always type them: the fandom, the character, the ship, the post type, a joke tag, two "my art" variants, and a few more because the box was still open.
Now try to answer a simple question. Which of those tags brought you any notes?
You can't, and it isn't your fault. Tumblr shows you how many notes a post got, but nothing anywhere tells you which tags did the work. This post covers how tagging actually works on Tumblr, why the tags you use most are rarely the ones that perform best, and a manual method for finding the Tumblr tags that get notes on your own blog, using nothing but a spreadsheet.
How Tumblr tags actually work
Two numbers matter here, and most people only know one of them.
You can add up to 30 tags to a post. Each tag can be up to 140 characters long. The box will keep accepting tags until you hit 30, which makes tagging feel free.
Only the first five are indexed in tag search. That's the number that matters for discovery. When someone browses a tag page or searches a tag, your post can only appear under the first five tags you attached. Tags six to thirty still work on your own blog (they power your /tagged/ pages and help you file things), but nobody new will find your post through them.
Tumblr has never been loud about this, and you'll find old posts claiming 10 or 20. Five is the figure most creators work to. Our free Tumblr tag analyzer uses the same cutoff and shows you exactly which of your tags land past it.
That means your tags are really doing two different jobs:
- Discovery tags (your first five) put the post in front of people who don't follow you yet.
- Organisational and commentary tags (everything after) are for you and your existing followers. The rambling tags where people put their actual reactions live here, and that's fine.
So the question isn't "how many tags should I use?" It's "which five go first?" The rest of this post is about answering that with evidence instead of habit.
Why your most-used tags aren't your best tags
Ask a creator for their best tag and they'll usually name the one they use most. That's almost never the same thing.
A tag becomes your most-used because it's on everything. And a tag that's on everything will, by definition, average out to roughly your blog's normal note count. It isn't helping or hurting. It's just there. You can't learn anything about a tag you never post without.
The tags worth finding are the ones that don't follow that pattern:
- Earners. Tags whose posts consistently get more notes than your typical post.
- Dead weight. Tags you keep using whose posts consistently come in below your typical post. Often these are huge tags where your post drops off the page in minutes, or tags nobody browses.
- Passengers. Tags that track your average because they're on every post. Not useless, but not telling you anything either.
Tumblr's interface can't separate these for you. The Activity page tells you a post got notes, never which tags did the work. You have to build the comparison yourself.
The manual method: find the tags that get notes
This takes about an hour the first time. After that it's a few minutes whenever you want to update it.
Step 1: Pick 20 to 30 of your own posts
Use original posts only, not reblogs of other people's content. A reblog's notes mostly belong to the original poster and will muddy everything. Pick posts that are at least a week old so their note counts have mostly settled.
Step 2: Log one row per tag, not one row per post
This is the step that makes the rest easy. For each post, write one row for each of its first five tags, with the post's note count repeated on every row:
Post,Tag,Notes,Reblogs
Sketch Mar 3,art,142,61
Sketch Mar 3,original character,142,61
Sketch Mar 3,digital art,142,61
Comic Mar 9,art,38,9
Comic Mar 9,webcomic,38,9
(Example numbers, not real data.)
Since October 2025, Tumblr shows likes, reblogs, and comments separately on a post, so grab the reblog count while you're there. It matters in step 4.
If you don't know a post's exact tag order, paste your blog into the tag analyzer. It lists the tags on your 20 most recent posts in the order you added them.
Step 3: Average each tag
In Google Sheets or Excel, put your tag list in a column and calculate two numbers for each one. With tags in column B and notes in column C:
- Uses:
=COUNTIF(B:B, "art") - Average notes:
=AVERAGEIFS(C:C, B:B, "art")
Swap "art" for a cell reference and drag the formula down. (Google's AVERAGEIFS docs cover the syntax if you want to add more conditions, like only counting posts from the last three months.)
Then work out your blog's median notes per post across the whole sample. The median is better than the average here, because one post that went viral will drag the average up and make every other tag look bad.
Step 4: Compare, and filter out the noise
Sort by average notes and compare each tag to your median. Before you draw any conclusions, apply three rules:
- Ignore tags with fewer than five uses. One lucky post makes a tag look brilliant. One quiet Tuesday makes it look dead. Below five uses, you're measuring the post, not the tag.
- Check reblogs, not just notes. Likes mostly come from people who already follow you. Reblogs are how a post travels to people who don't. A tag whose posts get an unusually high share of reblogs is more likely to be doing discovery work.
- Watch for tags that just track content type. If every post tagged "digital art" is a finished illustration and every "sketch" post is a quick doodle, the gap between those tags may be about the work, not the tag. Compare tags within the same kind of post where you can.
What's left is a short list: a few tags that consistently beat your median, a few that consistently fall short, and a lot of passengers.
Turn the results into a test
The spreadsheet tells you what's correlated with notes. To find out what's actually causing them, change one thing at a time.
Keep four of your first five tags the same and rotate the fifth slot. Run each candidate tag on five or six comparable posts, then check its average against your median again. Move your earners into the first five and push dead-weight tags past position five (or drop them) and see whether your typical post moves.
Two weeks of deliberate tagging will teach you more than two years of tagging from memory.
Keeping it going without the spreadsheet
The manual method works, but it has a cost. Every new post means more rows, note counts keep changing after you log them, and the sample stays small because nobody wants to log 300 posts by hand. Most people do it once and stop.
This is the problem we built Rebloq's tag analytics for. Once you connect a blog, it syncs your post history and keeps average notes and average reblogs per tag up to date automatically. It flags tags you keep using that consistently underperform, and recommends the ones that do well for you. It's on every plan, including Standard. Same method as above, just running all the time instead of once.
None of this is hidden data, by the way. Tags and note counts are all available through Tumblr's public API. Tumblr just doesn't add them up for you. If you want to see what else is out there, we compared the options in the best Tumblr analytics tools.
Quick answers
How many tags can you put on a Tumblr post? Up to 30, and each tag can be up to 140 characters. Only the first five are indexed in Tumblr's tag search, so tags six to thirty organise your own blog but won't help anyone new find the post.
Do more tags get more notes on Tumblr? Not past five. Tags after the fifth aren't indexed in tag search, so they can't bring in new readers. What changes your notes is which five tags you pick and the order you put them in.
What are the best Tumblr tags for getting notes? There's no universal list. A tag that works for one blog does nothing for another, because it depends on your audience and the kind of posts you make. The only reliable way to find yours is to compare average notes per tag across your own posts.
How many posts do I need before tag data means anything? Treat any tag you've used fewer than five times as unknown. One lucky post can make a tag look brilliant, and you need several uses before its average tells you anything about the tag rather than the post.
The bottom line
Tags are the one part of a Tumblr post that's entirely about reaching people who don't follow you yet, and almost everyone picks them on autopilot.
The fix isn't more tags. It's five deliberate ones at the front, chosen because your own posts show they work. Log 20 posts, average your tags, ignore anything with fewer than five uses, and test one slot at a time.
Start by running your blog through the free tag analyzer to see which of your tags are falling past the first five right now. If you'd rather have the per-tag numbers tracked for you, Rebloq has a free 7-day trial.