This repository provides a custom-tailored Docker image of Mastodon with an increased character limit. Instead of the default 500 characters, this version allows up to 3,000 characters per status update.
- Extended Limit: 3,000 characters for posts.
- Auto-Update: A GitHub Action checks daily for new official Mastodon releases and rebuilds the image automatically if an update is found.
- Reliable Base: Built directly on top of official
tootsuite/mastodonimages to ensure maximum compatibility and stability.
To enable extended character limits, update your docker-compose.yml etc. by replacing the official image with this custom build.
Replace all occurrences of the main image (example for version v4.5.8):
From:
docker.io/tootsuite/mastodon:v4.5.8
To:
ghcr.io/komplix/mastodon-extended:v4.5.8
Do not change the streaming image. It should remain the official one, as it does not require the character limit patch:
docker.io/tootsuite/mastodon-streaming:v4.5.8
If you encounter any issues, you can switch back to the official image at any time.
- Existing posts with up to 3,000 characters will remain intact and visible.
- New posts will simply be restricted to the default 500-character limit again.
docker pull ghcr.io/komplix/mastodon-extended:v4.5.8
The build process patches the validation logic during the Docker build stage using a sed command:
- Target File: /opt/mastodon/app/validators/status_length_validator.rb
- Modification: Replaces MAX_CHARS = 500 with MAX_CHARS = 3000.
This image patches the Server-Side Validation.
- Federation: Your server will successfully accept and federate 3,000 characters.
- Frontend: The web interface (browser) may still show a countdown starting at 500 or turn red after 500 characters. This is a visual-only limitation; your posts will still be saved and published correctly up to the 3,000-character limit.
This project follows the licensing of the original Mastodon project.