LinkedIn's help pages blocked our checker, so the organic specs below come from recent guides that cite LinkedIn. The video ad specs are from LinkedIn's official ads page.
Organic posts
| What | Spec | Confidence |
|---|---|---|
| Post text | 3,000 characters. The "see more" cut-off is at roughly 140–210 characters on mobile. | Widely reported |
| Single image | 1080 × 1350 (4:5) or 1080 × 1080. LinkedIn displays images up to 4:5. | Third-party guide (Jun 2026) |
| Multi-image | Up to 20 images | Third-party guide |
| Document post (PDF carousel) | Up to 100 MB. Up to 300 pages Check in-app. Design at 1080 × 1080 or 1080 × 1350. | Third-party guide |
| Video length | 3 seconds to 15 minutes from desktop. Mobile has been 10 minutes; one 2026 guide says 15 minutes on every device. Check in-app | Mixed |
| Video ratio | 1:2.4 to 2.4:1. Vertical 9:16 and 4:5 work well on mobile. | Third-party guide |
| Video file | MP4 with H.264, 30 fps recommended, up to ~5 GB | Third-party guide |
| Link preview image | 1200 × 627 (1.91:1) | Third-party guide |
Video ads (official)
- Ratios: 4:5, 9:16, 16:9 and 1:1.
- Length: 3 seconds to 30 minutes.
- File: 75 KB to 500 MB, MP4, 30 fps.
- Captions are optional but recommended.