OpenPostMedia limits
Default attachment limits used by OpenPost before publishing.
These defaults apply before publishing. The destination preview shows account-specific limits and readiness.
Sizes are exact bytes, durations are seconds, and attachment counts apply to each thread segment. A dash means no fixed catalogue limit, not unlimited. Your plan, server, account, or connected instance can impose lower limits.
Upload limits
Workspace uploads accept files up to 50 MB (52,428,800 bytes). Images must decode successfully and contain no more than 64 million (64,000,000 pixels). This bounds the memory needed to open compressed files. Destination publishing limits below are separate.
Default limits
| Destination format | Attachments | File types | Maximum bytes | Image maximum bytes | Video seconds | Additional rules |
|---|---|---|---|---|---|---|
| X thread | 0–4 | image/jpeg, image/png, image/webp, image/gif, video/mp4, video/quicktime | 8589934592 | - | 1200 | Video must be the only attachment |
| X image post | 1–4 | image/jpeg, image/png, image/webp, image/gif | - | - | - | |
| X video | 1–1 | video/mp4 | 8589934592 | - | 1200 | |
| Bluesky thread | 0–4 | image/jpeg, image/png, image/webp, video/mp4 | 300000000 | 2000000 | 600 | Video must be the only attachment |
| Bluesky images | 1–4 | image/jpeg, image/png, image/webp | - | 2000000 | - | |
| Bluesky video | 1–1 | video/mp4 | 300000000 | - | 600 | |
| dev/null images | 1–3 | image/jpeg, image/png, image/webp | 10485760 | - | - | |
| Mastodon thread | 0–4 | image/jpeg, image/png, image/webp, image/gif, video/mp4 | - | - | - | |
| Mastodon media | 1–4 | image/jpeg, image/png, image/webp, image/gif, video/mp4 | - | - | - | |
| Mastodon video | 1–1 | video/mp4, video/quicktime, video/webm | 103809024 | - | - | |
| Pixelfed thread | 0–4 | image/jpeg, image/png, image/webp, image/gif | - | - | - | |
| Pixelfed photo | 1–4 | image/jpeg, image/png, image/webp | - | - | - | |
| Pixelfed album | 2–4 | image/jpeg, image/png, image/webp | - | - | - | |
| PeerTube video | 1–1 | video/mp4, video/quicktime, video/webm, video/x-matroska | - | - | - | |
| Lemmy image | 1–1 | image/jpeg, image/png, image/webp, image/gif | - | - | - | |
| PieFed image | 1–1 | image/jpeg, image/png, image/webp, image/gif | - | - | - | |
| Threads thread | 0–10 | image/jpeg, image/png, image/webp, video/mp4, video/quicktime | - | - | - | Public HTTPS file required |
| Threads media | 1–1 | image/jpeg, image/png, image/webp | - | - | - | Public HTTPS file required |
| Threads carousel | 2–20 | image/jpeg, image/png, image/webp, video/mp4, video/quicktime | - | - | - | Public HTTPS file required |
| Threads video | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 180 | Public HTTPS file required; Aspect ratio: 9:16, 1:1 |
| LinkedIn image | 1–1 | image/jpeg, image/png, image/gif | - | - | - | |
| LinkedIn document | 1–1 | application/pdf, application/msword, application/vnd.openxmlformats-officedocument.wordprocessingml.document, application/vnd.ms-powerpoint, application/vnd.openxmlformats-officedocument.presentationml.presentation | 104857600 | - | - | |
| LinkedIn multi-image post | 2–20 | image/jpeg, image/png, image/gif | - | - | - | |
| LinkedIn video | 1–1 | video/mp4 | 524288000 | - | 1800 | |
| Facebook Page photo | 1–1 | image/jpeg, image/png, image/webp | - | - | - | Public HTTPS file required |
| Facebook multi-photo | 2–10 | image/jpeg, image/png, image/webp | - | - | - | Public HTTPS file required |
| Facebook Page Story | 1–1 | image/jpeg, image/png, image/webp, video/mp4, video/quicktime | - | - | - | Public HTTPS file required |
| Facebook Reel/video | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 180 | Public HTTPS file required; Aspect ratio: 9:16, 1:1 |
| Facebook video | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 43200 | |
| Instagram feed | 1–1 | image/jpeg, image/png, image/webp | - | - | - | Public HTTPS file required |
| Instagram carousel | 2–10 | image/jpeg, image/png, image/webp, video/mp4, video/quicktime | - | - | - | Public HTTPS file required |
| Instagram Story | 1–1 | image/jpeg, image/png, image/webp, video/mp4, video/quicktime | - | - | - | Public HTTPS file required |
| Instagram Reel | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 180 | Public HTTPS file required; Aspect ratio: 9:16, 1:1 |
| YouTube Short | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 180 | Aspect ratio: 9:16, 1:1 |
| YouTube video | 1–1 | video/mp4, video/quicktime | 2147483648 | - | 43200 | |
| TikTok video | 1–1 | video/mp4, video/quicktime, video/webm | 4294967296 | - | 600 | Public HTTPS file required; Aspect ratio: 9:16, 1:1 |
| TikTok photo post | 1–35 | image/jpeg, image/webp | 20971520 | - | - | Public HTTPS file required |
| Pinterest Pin | 1–1 | image/jpeg, image/png, image/webp | 20971520 | - | - | Public HTTPS file required |
| Pinterest multi-image Pin | 2–5 | image/jpeg, image/png, image/webp | 20971520 | - | - | Public HTTPS file required |
| Pinterest video Pin | 1–1 | video/mp4 | 2147483648 | - | 900 | |
| Google Business photo update | 1–1 | image/jpeg, image/png | - | - | - | Public HTTPS file required |
| Telegram media | 1–10 | image/jpeg, image/png, image/webp, image/gif, video/mp4, video/quicktime, application/pdf | - | - | - | |
| Telegram video | 1–10 | image/jpeg, image/png, image/webp, image/gif, video/mp4, video/quicktime, application/pdf | - | - | - | |
| Discord attachment | 1–10 | image/jpeg, image/png, image/webp, image/gif | 10485760 | - | - | |
| Discord video | 1–1 | video/mp4, video/quicktime, video/webm | 10485760 | - | - |
Provider exceptions
Reviewed 26 September 2026. The table above comes from OpenPost's capability catalogue. Preflight also checks codecs, dimensions, and account restrictions.
| Provider | What to check |
|---|---|
| Bluesky | A segment can contain images or one video. |
| X | Premium and verified accounts can have higher video limits. The destination preview applies them. |
| TikTok | The connected creator determines duration and privacy options. URL uploads need a verified domain and accessible HTTPS file. |
| YouTube | OpenPost's default size cap is lower than the API maximum. Unverified API projects may be limited to private uploads. |
| Video permissions differ from image and document permissions. | |
| Mastodon and Pixelfed | The connected instance's advertised limits override defaults. |
| PeerTube | Instance quota and transcoding policy apply. |
| Lemmy and PieFed | Community posts need a title. Lemmy API v4 instances are not supported. |
| Telegram | Limits depend on the sending method and hosted or local Bot API. Not every transfer limit appears above. |
For access or approval failures, see connecting accounts and the integration setup guides.