Schedule and bulk publish Mastodon posts

BulkPublish is a social media scheduler built for people who post to Mastodon a lot. Connect your account once and you can plan a content calendar, auto-post on a repeating queue, and bulk upload a month of content in one go, whether you work from the app, a CSV, an RSS feed, the REST API or an AI agent. The same click can cross-post to every other network you have connected.

What you can publish to Mastodon

BulkPublish supports 1 Mastodon post type. It is checked before it is queued, so a post Mastodon would reject never reaches your content calendar.

Post typeMedia
Post Optional, up to 4 images or videos

Mastodon limits and specs

These are the character limit, image sizes and video specs BulkPublish checks before a post is queued. They match what Mastodon itself accepts.

LimitValue
Caption length500 characters
Image formatsJPG, JPEG, PNG, WEBP, AVIF, HEIF, GIF
Max image size16 MB
Images per post4
Video formatsMP4
Max video size99 MB
Max video length5 minutes
ThreadsSupported. Longer text is split across a numbered thread

Mastodon analytics

Every published post is checked for its numbers, so Mastodon engagement sits next to every other channel in one dashboard instead of in Mastodon’s own tab.

  • Likes
  • Comments
  • Shares
  • Link clicks

How to connect Mastodon

  1. Create a BulkPublish account. The free plan connects three channels and does not ask for a card.
  2. Open Channels and choose Mastodon.
  3. Sign in with Mastodon and approve the permissions. BulkPublish stores the token, refreshes it on its own, and tells you if it ever needs reconnecting.
  4. Write a post, pick a time, and queue it. There is nothing else to install.

Ways teams use the Mastodon integration

  • Bulk upload a month of Mastodon posts from a CSV in one pass, then let the queue send them out at the times you set.
  • Write once and cross-post everywhere. The same post, adapted per network, goes to Mastodon and every other connected channel together.
  • Turn a blog or podcast RSS feed into an automatic Mastodon post the moment a new item appears.
  • Ask an AI agent to draft the week, review it in the content calendar, and approve it. The agent schedules to Mastodon through the MCP server.

Who publishes to Mastodon this way

Each of these has a page of its own, with the networks and the features that audience leans on.

Post to Mastodon from an AI agent

The hosted MCP server exposes 51 tools over OAuth 2.1, so Claude, ChatGPT, Grok, Cursor and any other MCP-compatible agent can draft, schedule, publish and read Mastodon analytics for you. There is no API key to paste and nothing to run locally.

See all supported agents

Mastodon API access

Everything on this page is available programmatically. One REST endpoint publishes to Mastodon and every other channel, with SDKs for Node and Python, a Postman collection, and first-party nodes for n8n, Zapier, Make and IFTTT.

Read the API docs

Free Mastodon tools

Free to use, no sign-up. They are handy while you are writing the post, and you can schedule the result here when you are done.

Browse all free tools

Frequently asked questions

Can I schedule Mastodon posts in advance?

Yes. Pick any future time in your own timezone, or drop the post into a recurring queue slot and BulkPublish picks the next opening for you. Scheduled posts publish on their own, so nothing on your phone has to be awake.

Can I auto-post to Mastodon automatically?

Yes. A recurring queue publishes on a repeating weekly pattern without you choosing a date each time, and an RSS feed can auto-post to Mastodon the moment a new item appears. Both run on our servers, so they keep working while you are offline.

How many Mastodon posts can I schedule at once?

As many as your plan allows. Bulk Compose takes a CSV or a pasted list and turns it into a full schedule in one pass, so a month of Mastodon content is one upload rather than thirty separate posts.

Can I plan a content calendar for Mastodon?

Yes. The calendar shows every scheduled post across all your channels at once, so you can see what is going out on Mastodon next to everything else, drag a post to a new slot, and spot the gaps before they happen.

What is the Mastodon character limit?

500 characters per post. BulkPublish counts as you type and blocks anything over the limit before it is queued, so you find out while you are writing instead of when the post fails.

Can I post to more than one Mastodon account?

Yes. Connect as many Mastodon accounts as your plan allows, group them into channel sets, and publish to the whole set at once. Each account keeps its own schedule, its own analytics and its own token.

Do I get Mastodon analytics?

Published posts are checked for their numbers and shown next to every other channel, so you can compare Mastodon engagement against the rest without switching tabs. Link clicks are measured by BulkPublish itself, so they are available even where Mastodon reports nothing.

Is there a free Mastodon scheduler plan?

Yes. Three channels and thirty posts a month, with no card required. Mastodon counts as one channel per connected account.

Still stuck? The Help Center walks through it step by step.

BulkPublish publishes to 15 networks. Every one has a guide like this.

Start publishing to Mastodon

Connect your account and schedule your first post in a couple of minutes. Free plan, no card, cancel whenever you like.

Get started free See pricing