The short answer
Relevance beats volume everywhere. Use a few tags that describe exactly what the post is about, plus one or two broader tags for reach.
Platform by platform
- Instagram: up to 30 are allowed, but Instagram’s own guidance points to 3–5 highly relevant tags. Treat a big cluster as a testing pool and keep what performs in Insights.
- TikTok: 3–6 tags. TikTok uses them to categorise your video, so describe the content rather than chasing #fyp.
- X (Twitter): 1–2. Every character counts, and long tag lists look like spam.
- LinkedIn: 3–5 professional tags — one industry, one topic, one or two niche.
- YouTube: the Tags field matters little compared with your title and thumbnail; use a handful of long-tail phrases and up to 3 hashtags in the description (more than 15 are ignored).
- Facebook: a few relevant tags help Reels and Groups discovery; long lists rarely help organic posts.
Mix broad and niche
A huge tag like #fitness has millions of posts, so yours disappears in seconds. A specific tag like #homeworkoutforbeginners has a smaller but far more interested audience. A good set combines both — the hashtag generator builds that mix automatically for each platform.
Rotate, don’t repeat
Pasting the identical block on every post can look automated. Generate a few alternative sets and rotate them, and check a tag on the platform before using it in a campaign — individual tags are occasionally restricted.