Short answer: all three take vertical 9:16 video, but they differ on length, captions and rules. Shorts max out at 3 minutes and use a 100-character title. Reels run up to 3 minutes in the app (15 minutes via Meta's API), with 2,200-character captions and a five-hashtag cap. TikTok allows 10 minutes via its API and longer in the app for some creators, with the longest captions. All three favor original content, so post your own clean file to each.
Specs side by side
| TikTok | Instagram Reels | YouTube Shorts | |
|---|---|---|---|
| Max length | 10 min via API; up to 60 min in app per coverage | 3 min in app; 15 min via API | 3 min |
| Aspect ratio | 9:16 recommended | 9:16 recommended | Square or vertical |
| File size | 4 GB via API | 300 MB via API | Not stated on pages checked |
| Formats | MP4, WebM, MOV | MP4, MOV | — |
| Caption / title | 2,200 via API; 4,000 in app per third-party | 2,200 | Title 100, description 5,000 |
| Hashtags | No published max found | Moving to 5 | More than 60 and all are ignored |
| Photo posts | Photo mode slideshows | Carousels (not Reels) | — |
| Accounts in one app | Not stated on pages we could load | Up to 5 | Up to 100 channels per Google Account |
Sources, all as of September 2026: TikTok media specs, caption limit, 60-minute test; Instagram API specs, 3-minute Reels, hashtag cap, five accounts; YouTube Shorts length, title limits, hashtags, 100 channels.
Detail pages: TikTok video specs, Instagram Reels specs, Shorts requirements.
Rules and health tools
| TikTok | YouTube | ||
|---|---|---|---|
| Where to check standing | Account status, Account Check | Account Status | YouTube Studio notices |
| Reach limit for allowed content | Not eligible for For You feed | Not eligible for recommendation | — |
| Originality | Watermarked and unoriginal content ineligible for FYF | Recommends originals over identical reposts | Reused content policy; spam policy on mass-produced content |
| Strikes | Expire after 90 days | — | 3 strikes in 90 days may end a channel |
Sources: TikTok FYF standards and enforcement update; Instagram Account Status and original content update; YouTube spam policy and reused content. All as of September 2026.
Which to prioritize
There is no universal winner; it depends on where your audience already is.
- TikTok if your content is native to its trends and you want the longest captions and photo slideshows.
- Reels if your audience or customers are on Instagram, and you can live with five hashtags.
- Shorts if you also make long-form YouTube videos, or want search traffic on YouTube.
- All three if you can make one clean master and adapt captions per platform. See cross-posting without watermarks.
Posting to all three with Farmero
Farmero posts TikTok videos and photo slideshows, Instagram Reels and YouTube Shorts through the real apps on your own iPhones. Drop a clip once, pick accounts across the three, and each becomes its own editable card with its own caption and settings; Farmero confirms each post on the profile or channel before marking it posted. See Posting. Automating these apps may breach their terms, and nobody can promise an account will never be restricted.
FAQ
Which is longer, TikTok, Reels or Shorts?
TikTok allows the longest videos. Reels and Shorts both top out at three minutes in their apps, as of September 2026.
Can I post the same video to TikTok, Reels and Shorts?
Your own original video, yes. Upload the clean file to each rather than a download with another app's watermark.
Which has the strictest hashtag rule?
Instagram, which is moving to five per reel or post.
Which platform shows the most about account standing?
TikTok and Instagram both have in-app status pages. YouTube shows warnings and strikes in YouTube Studio.