Limits
post.buzz enforces two layers of limits. Both are checked before a post is published, so you get a clear error instead of a platform rejection.
- Platform limits — per-platform constraints on media and text.
- Plan limits — per-account resource ceilings (channels, posts/month, file sizes, AI actions).
How validation works
When you create a post (via the app or the REST API), the
post is validated against the destination platform's rules for its postType:
- Aspect ratio —
width / height. - Bitrate —
(fileSize × 8) / videoLength, in bps (shown as Mbps). - File count — how many images/videos a single post may attach.
- Resolution, duration, file size.
- Text length — per-platform and per-tier (e.g. X free vs. premium).
If anything fails, the API returns 400 with a message naming the constraint.
Ownership failures (referencing an account or media you don't own) return
403. See Errors.
Platform limits — quick reference
Global upload ceiling: 5 GB video / 25 MB images / 100 MB documents. Per-platform limits are often lower — the smaller of the two is enforced.
| Platform | Max files | Video max | Video duration | Image max |
|---|---|---|---|---|
| Instagram Post | 10 | 45 Mbps | 15 min | 8 MB |
| Instagram Reel | 1 | 45 Mbps | 15 min | — |
| Instagram Story | 1 | 100 MB | 60 s | 8 MB |
| TikTok Video | 1 | 1 GB | 10 min | — |
| TikTok Photo | 10 | — | — | 20 MB |
| YouTube Short | 1 | 5 GB | 3 min | — |
| YouTube Video | 1 | 5 GB | 4 h | — |
| 10 | 2 GB | 30 min | 5 MB | |
| X | 4 | 512 MB | 140 s / 600 s¹ | 5 MB |
| Facebook Post | 10 | 45 Mbps | 8 min | 4 MB |
| 1 | 2 GB | 15 min | 5 MB | |
| 1 / 10 gallery | 1 GB | 15 min | 20 MB | |
| Threads | 10 | 1 GB | — | 8 MB |
| Discord | 10 | 25 MB | — | 25 MB |
| Slack | 4 | 1 GB | — | 1 GB |
| Mastodon | 4 | 99 MB | — | 16 MB |
| Bluesky | 4 | — | — | — |
| Google Business | 1 | — | — | 5 MB |
¹ X video duration depends on account tier: 140 s (Free/Basic) or 600 s (Premium/Premium+).
For full per-post-type detail (aspect ratios, resolutions, text limits), see the individual platform pages.
Plan limits
Your plan determines resource ceilings. These are separate from platform media limits and apply to everyone on the plan.
| Free | Starter | Pro | |
|---|---|---|---|
| Members | 1 | 5 | 50 |
| Channels (accounts) | 3 | 10 | 30 |
| Posts / month | 30 | 400 | Unlimited |
| Media uploads | 20 | 200 | 1,000 |
| Max image size | 10 MB | 25 MB | 25 MB |
| Max video size | 25 MB | 100 MB | 100 MB |
| AI actions / day | 50 | 200 | Unlimited |
null means unlimited. The per-plan maxFileSize is the upload ceiling for
your account; it can be lower than the global ceiling but never higher.