Instagram enforces a hard cap of 5 hashtags per post, rolled out in December 2025. That is a genuine technical limit, not a suggestion, and it is one of three very different rules covered here: an enforced cap, a silent drop-off, and a platform with no limit at all but a strong best-practice range anyway.
Instagram: enforced, hard cap of 5
Instagram now caps hashtags at 5 across posts and Reels, combined between the caption and the first comment, not per location. Meta's own guidance was already narrower than that before the cap arrived: 3 to 5 highly relevant tags, not the maximum you can cram in. Place them in the caption itself rather than the first comment. Source: Instagram's Help Center, "Use hashtags on Instagram."
YouTube Shorts: no visible cap, but everything past 15 vanishes
YouTube has no interface limit stopping you from typing more, but once a video's hashtags cross 15, YouTube ignores every hashtag on that video, not just the ones over the line. Going over does not waste space; it erases the tags that would have worked. Place hashtags in the description (the first three also surface above the title), and if you are uploading a vertical video, include #Shorts, since YouTube expects it on every vertical upload. Source: YouTube Help, "Find playlists & videos using hashtags."
TikTok and LinkedIn: no published limit, same practical range
Neither TikTok nor LinkedIn publishes a hard hashtag cap. Both, independently, converge on the same practical guidance: 3 to 5 specific, relevant tags outperforms a long list, based on each platform's own creator guidance and 2026 engagement data. There is no technical wall to hit here, but a wall of 20 generic hashtags reads as spam to the algorithm and to a human scrolling past it, on either platform.
The pattern underneath all four
- Instagram: enforced. Hard-stop at 5, no exceptions.
- YouTube Shorts: ignored beyond. No stop, but everything past 15 gets silently dropped.
- TikTok: none published. No wall, but 3 to 5 relevant tags is what the data supports.
- LinkedIn: none published. Same story as TikTok.
Across every platform here, and for any platform not listed, 3 to 5 specific, on-topic hashtags is the range that keeps showing up, whether as an enforced rule or as what actually performs best. A shorter, sharper list of relevant tags reliably beats a long, generic one, and on Instagram specifically, going past 5 is no longer optional to avoid: the post will not let you.
Build a platform-specific set with the right count and placement already applied: Hashtag Generator.