Social Media Character Limits
This guide summarizes the most relevant text limits for each social network supported by Upload-Post. Keep these constraints in mind when building payloads so posts are accepted without truncation.
Facebook Character Limits
| Property | Description |
|---|
| post | 63,206 characters maximum |
| title | Reels title – 255 characters maximum |
Instagram Character Limits
| Property | Description |
|---|
| post | 2,200 characters maximum |
| altText | 1,000 characters maximum per image |
| comment | 2,196 characters maximum |
LinkedIn Character Limits
| Property | Description |
|---|
| post | 3,000 characters maximum |
| title | 400 characters maximum |
| comment | 1,250 characters maximum |
TikTok Character Limits
| Property | Description |
|---|
| post | 2,200 characters maximum |
Pinterest Character Limits
| Property | Description |
|---|
| post | 500 characters maximum |
| title | 100 characters maximum |
| link | 2,048 characters maximum |
| altText | 500 characters maximum |
Reddit Character Limits
| Property | Description |
|---|
| post | 5,000 characters maximum |
| title | 300 characters maximum |
| comment | 10,000 characters maximum |
Threads Character Limits
| Property | Description |
|---|
| post | 500 characters maximum |
| Property | Description |
|---|
| post | 280 characters maximum |
| post (Premium) | 25,000 characters maximum for Premium and Premium Plus accounts |
| altText | 1,000 characters maximum per image |
| subTitleName | 150 characters maximum |
YouTube Character Limits
| Property | Description |
|---|
| post | 5,000 characters maximum |
| youTubeOptions > title | 100 characters maximum |
| youTubeOptions > tags | 500 characters total, 2+ characters each |
| youTubeOptions > subTitleName | 150 characters maximum |
API Considerations
- Upload-Post validates payload sizes before sending them to social networks whenever limits are known. Requests that exceed the documented limits return a validation error.
- Some platforms might truncate overlong text instead of rejecting it (Meta products and YouTube occasionally do this). Inspect the per-platform response inside
results to confirm the final content.
- For channels with strict limits such as X, consider shortening URLs in your application prior to calling the Upload-Post API.
Updates and Changes
Social networks regularly adjust their limits. We keep this page aligned with the latest behavior we observe in production, but you should also:
- Check Upload-Post API responses for detailed error messages about rejected posts.
- Subscribe to our release notes for platform updates.
- Revisit this reference periodically, especially before large content campaigns.