How the YouTube checker works
What it checks
Title length with the likely cut-off points, description length with the part shown before "more", total tag length, ALL CAPS words and runs of punctuation in the title, a chapter list, a link, a call to action, whether the main title keyword opens the description, and the hashtag count.
The main keyword is the first meaningful word in your title after common filler words are removed. If it is not the word you care about, move it earlier in the title.
Sources
Per YouTube's help center, checked October 2026: title limit 100 characters and description limit 5,000 characters (Add video info), chapter rules (Video Chapters), and hashtag rules (Find playlists and videos using hashtags, support.google.com/youtube/answer/6390658): from the hashtags in your description, up to three of the most engaging appear by the video title, and a video with more than 60 hashtags has every hashtag ignored. The 500 character tag limit is in the YouTube Data API reference for the videos resource.
Not official, so labeled approximate throughout: the title cut-off near 70 characters on desktop and 60 on mobile, and the roughly 150 description characters shown before "more". They vary with screen width and layout.
Limitations
Call to action and clickbait checks are pattern matches, so they can miss unusual phrasing. The tool cannot see your video, so it cannot tell whether the chapter times match the footage.
Frequently asked questions
What is the YouTube title character limit?
A title can be up to 100 characters, per YouTube's help center (checked October 2026). Titles over about 70 characters on desktop, and fewer on mobile, are likely to be cut with an ellipsis in search results and suggested videos. That cut point is approximate.
How long can a YouTube description be?
Up to 5,000 characters. Only roughly the first 150 characters show before the "more" link in most views, so the keyword and the main reason to watch should come first. The 150 figure is approximate.
What makes video chapters work?
Per YouTube's Video Chapters help page, the first timestamp must be 00:00, there must be at least three timestamps in ascending order, and each chapter must be at least 10 seconds long. The tool validates a pasted list against all three rules.
How many hashtags can I use on a YouTube video?
Up to three of the hashtags in your description appear above the title. If a video has more than 60 hashtags, YouTube ignores every one of them, per its help page on hashtags. Three focused hashtags is the safe number.
What is the limit for YouTube tags?
Tags are capped at 500 characters in total, per YouTube's Data API reference. This tool adds up each tag plus a comma between tags, which is close to how the total is counted. YouTube says tags play a minimal role in discovery, mainly for commonly misspelled topics.
Why check that the title keyword is in the first 150 characters?
Those characters are the only description text most viewers see before expanding. Repeating the main title word there tells viewers they are in the right place. This is an editing rule of thumb, not a published YouTube requirement.