Mastodon, on any server
Schedule Mastodon posts and threads on any server
Connect an account on mastodon.social or any other server, schedule single posts or full threads, add custom video thumbnails and, on Premium and higher plans, keep up with replies in the unified inbox.
Free for 7 days. Card required; cancel before the trial ends and you will not be charged.
- Mastodon
Mastodon in Postocial
Mastodon support that fits how the fediverse works
Mastodon is made of many independent servers, each with its own settings. Postocial connects accounts on any of them.
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Any server, one workspace
Whether your account lives on a large general server or a small community one, connect it and schedule like any other channel.
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Threads, published in order
Write a multi-part thread in the composer and Postocial publishes the parts in sequence at the time you set.
Scheduling and calendar -
Custom video thumbnails
Choose the preview image for your video instead of the default frame.
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Replies in one inbox
Answer Mastodon replies next to the rest of your conversations, with notes and assignments for your team. Included on Premium and higher plans.
Unified inbox -
RSS to Mastodon
Share each new release note or blog article with an RSS campaign when it appears in your feed.
Bulk posts and RSS -
Hashtag groups in CamelCase
Save the hashtags you use on Mastodon as hashtag groups, written in CamelCase so screen readers say each word.
Example
A sample week on Mastodon
How an open-source project might keep its Mastodon followers up to date.
| Day | Post | Set up in Postocial |
|---|---|---|
| Monday | Release announcement | Thread of four posts, scheduled for the release time |
| Tuesday | Demo video of the new feature | Custom video thumbnail |
| Thursday | Blog post on the roadmap | Shared by an RSS campaign |
| Friday | Questions from the community | Answered from the unified inbox (Premium and higher plans) |
Best practices
Mastodon best practices
Habits that make posts readable and welcome across Mastodon servers.
- Check your server's limits. 500 characters is only the default, and server admins can change it.
- Describe every attachment. Media descriptions make images and videos usable for people with screen readers.
- Write hashtags in CamelCase. #SmallBusinessTips reads correctly in a screen reader, while #smallbusinesstips does not.
- Post full links. Every link counts as 23 characters whatever its length, so shorteners save nothing and hide where the link goes.
- Default characters
- 500
- Characters per link
- 23
- Images per post
- 4
- Video file size
- 99 MB
Platform limits
Mastodon limits and media specs
The limits and sizes Mastodon sets for text, images and video, with a source for each. Platforms change them often, so check before a big campaign.
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Mastodon character limits
Field Maximum Post (default) 500 characters Reply (default) 500 characters Bio 500 characters Display name 40 characters Username 30 characters About the text limit. 500 characters is the default, but each server can change it, so read the server's /api/v2/instance configuration before posting. Every link counts as 23 characters, and for a mention only the username part counts.
Hashtags. Hashtags let anyone searching for that tag find the post. They can contain letters, numbers and underscores, but can't be numbers only.
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Mastodon image sizes
Placement Size Aspect ratio Post imagePNG, JPG, HEIF, WEBP or AVIF up to 16 MB, downscaled to about 8.3 megapixels (3840x2160). Up to 4 images per post. Animated GIFs: up to 16 MB, under 1 megapixel, one per post. Not specified Any AvatarCropped to 400x400. Up to 8 MB per the Mastodon source code. 400 × 400 px 1:1 Header1500x500 header dimensions. Up to 8 MB per the Mastodon source code. 1500 × 500 px 3:1 -
Mastodon video specs
Placement Max length Max file size Aspect ratio Video attachmentMP4, M4V, MOV or WebM up to 99 MB, transcoded to H.264. One video per post. mastodon.social limits frames to 8,294,400 pixels (3840x2160) and 120 fps. No duration limit is documented. Not stated 99 MB Any -
Sources
Checked on . Where Mastodon publishes no number, the notes in the tables say where a figure comes from.
Get connected
How to connect Mastodon
Any Mastodon server works. The connect accounts guide shows the steps. Managing an account for a client? Send a client invite link so they can connect it themselves, without sharing a password.
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Name your server
Tell Postocial which server your account lives on, such as mastodon.social.
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Approve access
Sign in on your server's own page and approve Postocial's access.
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Set your time slots
Pick the weekly times you want posts to go out. See the posting schedule guide.
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Schedule posts or threads
Write a single post or a thread, add media and schedule it.
Free tools
Free Mastodon tools
Free browser tools for getting posts ready before you schedule them.
Mastodon character counter
Check a post against Mastodon's default 500-character limit.
Mastodon image resizer
Resize images for your 400 × 400 avatar and your 1500 × 500 header.
Text styler
Style your Mastodon bio, which holds 500 characters, with Unicode letters.
FAQ
Questions about Mastodon scheduling
Something else on your mind? Email us at hello@postocial.com.
Does Postocial work with my Mastodon server?
Yes. Postocial connects Mastodon accounts on any server, not just mastodon.social.
What is the character limit on Mastodon?
500 characters by default, but each server can set its own. Links always count as 23 characters, and for mentions only the username counts, not the server name.
Can I schedule Mastodon threads?
Yes. Add every part of the thread to one post in the composer. The first part goes out at the time you picked and the rest follow as replies beneath it.
How many images can a Mastodon post have?
Up to 4 images, or one video, GIF or audio file. Images can be up to 16 MB and are scaled to about 8.3 megapixels. Videos can be up to 99 MB and are converted to H.264.
Can I answer Mastodon replies in Postocial?
Yes, on Premium and higher plans. Replies arrive in the unified inbox, where you can assign them, tag them and reply with saved replies or AI-suggested replies from your own AI key.
Can I mark Mastodon media as sensitive?
Yes. Tick Mark media as sensitive in the composer, and Mastodon hides the images or video behind a warning by default.
Do hashtags work on Mastodon?
Yes. Hashtags are how people searching for a topic find posts beyond your followers. They can use letters, numbers and underscores but cannot be numbers only. Write multi-word tags in CamelCase.
Keep your Mastodon followers in the loop
Connect your account on any server, schedule your next thread and, on Premium and higher plans, answer replies from one inbox.
A card is required to start the 7-day free trial. When the trial ends, we charge your card for the plan you picked, unless you cancel before.