What are YouTube tags?
YouTube tags are descriptive keywords you add to a video in YouTube Studio to help viewers find it. They live in their own field in the video's details, separate from the title and the description, and a video can have several of them.
They are also the most overrated field in YouTube Studio. YouTube's own help page is plain about it: "Tags can be useful if the content of your video is commonly misspelled. Otherwise, tags play a minimal role in your video's discovery."
What tags do and don't do
The same help page names what does the work instead: your video's title, thumbnail and description are more important pieces of metadata for discovery. Tags sit behind all three.
The case where they still help is the one YouTube gives. A game with a hard name, a dish with three spellings, a product people abbreviate: a viewer who types the name wrong may still reach a video tagged with that spelling. Outside that case, a long tag list mostly costs the time it took to write.
Two habits are worse than useless. Copying the tags of a bigger channel's video describes their video, not yours. And piling tags into the description breaks YouTube's policies on spam, deceptive practices and scams, which the help page says in so many words.
The 500-character limit
The tag list has one limit, and it is in characters, not in tags. YouTube's Data API documentation sets it at 500 characters for the whole list. The commas between tags count toward the limit. A tag that contains a space is handled as if it were wrapped in quotation marks, and those count too: "Foo-Baz" is seven characters, "Foo Baz" is nine.
Where you add them
For a new upload, the tags sit in the Details step, under More options. For a video already uploaded, open Content in YouTube Studio, select the video and click Show more. Tags can also be edited in the YouTube app.
Tags vs hashtags
| Tags | Hashtags | |
|---|---|---|
| Where they go | Their own field in Studio | The title or the description, after a # |
| Seen by viewers | No | Yes, up to three by the title |
| Clickable | No | Yes, they open a page of videos with the same hashtag |
| Limit | 500 characters in all | 60 per video, or YouTube ignores all of them |
Hashtags can't contain spaces, and YouTube's help asks for hashtags directly related to the video. Unrelated ones can get the video removed.
Why YouTube tags matter less than you'd think
Tags are the easiest field to fill and the one that changes the least. Viewers don't see them. Every viewer sees the thumbnail and the title, at feed size, next to a dozen other videos. If you have ten minutes before publishing, they belong to those two. Give tags the thirty seconds it takes to add the topic, its close variants and the misspellings people really type, and stop there.