Free tools

YouTube description checker

Paste a description to check it against YouTube's limits, see what viewers read before “Show more”, and test your hashtags, links, tags and chapter timestamps.

  • Free, no sign-up
  • Nothing you paste leaves your browser
  • Limits checked October 28, 2026
Everything stays in your browser.
0 / 5,000
0 / 500
Lets the checker test the last chapter.

Checks

Against YouTube's published limits and chapter rules, as read on October 28, 2026.

    What shows before “Show more”

    Approximations of YouTube's desktop layouts. On a phone, the description opens after viewers tap “more”.

    Hashtags found

    Clean copy

    Invalid characters and extra blank lines removed, the first chapter set to 0:00, duplicate tags dropped. Fixes that need a decision stay in the checks.

    Description
    Tags

    YouTube description limits, in one place

    Length
    5,000 characters5,000 bytes through the YouTube Data API
    Not allowed
    < and >YouTube Help; YouTube Data API
    Hashtags
    60 at mostMore than 60 and YouTube ignores all of them
    Chapters
    First at 0:00, 3 or moreIn ascending order, each at least 10 seconds
    Tags
    500 characters in totalCommas count; a tag with a space counts two quotation marks
    Links
    Clickable on eligible channelsSuch as verified channels or ones with advanced features

    Write it in two parts

    YouTube's own advice is to treat a description as two parts: what viewers see before they click “Show more” on a computer or “more” on a phone, and everything after. Open with a sentence or two that say what the video is about, in the words people search for. Links, credits, gear lists and chapters go underneath, where the people who want them will look.

    Characters or bytes?

    YouTube Studio counts 5,000 characters. The YouTube Data API, which scheduling and upload tools use, allows 5,000 bytes, and an emoji or a letter from many non-Latin scripts takes two to four bytes. A description that passes in Studio can fail through a tool, so the checker counts both.

    Hashtags and chapters

    Up to 60 hashtags are allowed across the title and description, and YouTube ignores all of them above that. Of the ones in the description, up to three that YouTube considers most engaging show by the title. Chapters come from timestamps in the description: the first at 0:00, at least three in order, each 10 seconds or longer. To build them from a list of times, use the YouTube timestamp link generator; for chapters on a long recording, our guide to turning a livestream into a video covers trimming and highlights.

    Checking the title too? The YouTube title checker shows where it gets cut off, and the upload checker runs the title, description, tags and chapters together. Our guide to YouTube SEO in 2026 covers what each part does for search.

    Sources: YouTube Help: Edit video settings · YouTube Help: Tips for video descriptions · YouTube Data API: Videos resource · YouTube Help: Find playlists & videos using hashtags · YouTube Help: Video chapters · YouTube Help: Add tags to your YouTube videos, read on October 28, 2026.

    Embed this checker

    Teachers, bloggers and course creators can put this YouTube description checker on their own page for free. Paste the code below into your page's HTML. It loads from markstudios.com, so it stays current when we update the numbers.

    Questions, answered.

    Anything else? Message Mark and you'll get a written reply within one business day.

    How long can a YouTube description be?

    5,000 characters in YouTube Studio. YouTube Help says video descriptions have a character limit of 5,000 characters and can’t include invalid characters. The YouTube Data API, which scheduling and upload tools use, counts 5,000 bytes instead, and emoji and many non-Latin letters take two to four bytes each.

    What shows before “Show more” in a YouTube description?

    Only the first lines. YouTube Help describes a description as two parts: what viewers see before clicking “Show more” on desktop or “more” on mobile, and what they see after. Use the first lines to say what the video is about, and put links, credits and chapters lower down.

    How many hashtags can a YouTube description have?

    Up to 60. YouTube Help says that if a video has more than 60 hashtags, YouTube ignores every hashtag on it, and over-tagging may remove the video from search. Of the hashtags in the description, up to three that YouTube considers most engaging appear by the title.

    Why aren’t my YouTube chapters showing?

    Check YouTube’s rules: the first timestamp must be 0:00 (YouTube Help writes it as 00:00), there must be at least three timestamps in ascending order, and each chapter must be at least 10 seconds long. Add the video’s length above and the checker tests the last chapter too.

    How do YouTube tags count toward the 500-character limit?

    All tags together can be 500 characters. The YouTube Data API counts the commas between tags, and a tag with a space counts as if it were wrapped in quotation marks, so “video editing” uses 15 characters. YouTube Help adds that tags play a minimal role in discovery unless the topic is commonly misspelled.

    Are links in my description clickable?

    Only on channels that meet YouTube’s requirements. The YouTube Data API says URLs in a description become clickable links when the channel meets platform-level requirements, such as channel verification or having advanced features enabled.

    Is my description sent anywhere?

    No. Everything runs in your browser, so you can check a description before the video goes live.

    Rather have every upload written for you?

    Mark writes the title, description and tags around what people search, sets the thumbnail and schedules each video, and you work directly with Mark.

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