Works, with rewrites

How to post from Mastodon to Telegram

You can, but not by copying the text across: 2 things change between Mastodon and Telegram, starting with you have 3,500 characters you are not using. Below is exactly what breaks and what to do instead.

Side by side

MastodonTelegram
Characters5004,000
Mediaoptionaloptional
Hashtags2-4 hashtags in CamelCase (#SocialMedia, not #socialmedia) for screen readersnot needed
Links in bodyfinefine
Needs platform approvalnono

What changes, one by one

You have 3,500 characters you are not using

Mastodon caps at 500 characters, Telegram allows 4,000. Posting the short version verbatim wastes the room Telegram gives you to actually explain the thing.

The hashtag rules are not the same

Mastodon: 2-4 hashtags in CamelCase (#SocialMedia, not #socialmedia) for screen readers. Telegram: not needed. Carrying the tag block across is the single most obvious sign of an automated cross-post.

Why copy-paste cross-posting underperforms

Mastodon is community-first; alt text on media is expected, not optional. Telegram is direct and clear; formatting is light. Those are different jobs, so the same words cannot do both well — and every algorithm here demotes text that obviously was not written for it. The fix is not to skip cross-posting; it is to send a native version to each network.

Publish to both in one call

curl -X POST https://postwire.io/api/post \
  -H "Authorization: Bearer $POSTWIRE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "platforms": ["mastodon", "telegram"],
    "text": "Your post",
    "per_platform": {
      "mastodon": { "text": "The Mastodon version" },
      "telegram": { "text": "The Telegram version" }
    }
  }'

PostWire's /api/generate writes those per-platform versions for you from a single prompt, respecting every limit in the table above. From an AI agent it is one MCP tool call.

Do this without writing the post twice

PostWire takes one idea and publishes a version written for each network — the right length, hashtags and format per platform. It also refuses posts that would fail, like a video network with no video, before they are queued.

Free for one brand — 30 posts a month, no card. Starter is $9/month for three brands and 300 posts. There is a REST API and an MCP server if you would rather automate it.

Start free — no card →

Questions people actually ask

Can I cross-post from Mastodon to Telegram?
You can, but not by copying the text across: 2 things change between Mastodon and Telegram, starting with you have 3,500 characters you are not using. Below is exactly what breaks and what to do instead.
What is the character limit difference between Mastodon and Telegram?
Mastodon allows 500 characters and Telegram allows 4,000.
How do I post to Mastodon and Telegram at the same time?
With PostWire, one API call publishes to both: POST /api/post with platforms set to ["mastodon","telegram"]. Or one MCP tool call from an AI agent.

Other pairs: Telegram to Mastodon · all combinations · which APIs need approval

Picking a tool for this? We compared the ones with a public API side by side in the alternatives guide, prices included.