Mastodon
Platform · this deep dive is built from the official pages of the platform itself and of the tools that support it.
Overview
Mastodon is not a single platform but software on which independent operators run their own servers, linked by the ActivityPub protocol. The server selection page says so directly: "each server is run by an independent organisation or person and may differ in its moderation policies".
The "About" section reports that the project was "formally incorporated as a gGmbH (the German form of a non-profit limited company) in 2021", but "lost its non-profit status when Germany excluded software projects from those that qualify"; in 2025 the transfer of the project to a new foundation began. Separately there exists Mastodon, Inc. — a 501(c)(3) organisation in the US. The address of the German legal entity is in Berlin; the author of the project is Eugen Rochko, who started in 2016.
The practical conclusion: Mastodon has no single owner, no single moderation policy and no single rate card. All of that is set by the administrator of your server.
Who's here
The platform publishes no overall audience figure: neither the home page nor the server catalogue contains a number of users or of servers. With a federated design there is no single counter by definition — the data exists only on each server separately.
The positioning is stated on the home page: "We will never show you ads or push profiles at you". The language mix depends on the server: in the preferences you can "show only posts in certain detected languages when viewing public timelines", and automatic translation, according to the documentation on the network, "requires the server to have translation service support configured, and is therefore not available on every server".
Getting started
First you pick a server. The sign-up guide describes three modes: open registration ("fill in a form with a username, an email address and a password"), by invitation, and with approval, where you have to explain to a moderator why you have come. Before registering, the documentation advises reading the server's policy on its /about/more page.
The address consists of a name and a domain — @alice@example.com; the same name may be taken on different servers. Following someone from another server works just as it does for someone on your own.
Verification is neither paid for nor granted by hand. According to the profile documentation, the profile has "4 rows where you can set a label and a value"; if the HTTPS link you give leads to a page that links back to the profile with the attribute rel="me", the field is marked with a tick. The display name is "up to 30 characters by default", the bio "up to 500 characters by default".
What you can publish
The default values from the posting documentation: "the default limit is 500 characters", and the domain part of mentions is not counted towards it. Attachments — up to 4 images, or one GIF animation or video, or one audio file. Sizes: images (PNG, JPG, HEIF, WEBP, AVIF) and GIFV — up to 16 MB, video (MP4, M4V, MOV, WebM) and audio (MP3, OGG, WAV, FLAC and others) — up to 99 MB. Polls: "up to 4 options", "each option up to 25 characters", running from 5 minutes to 7 days.
The words "by default" are the key ones here: an administrator can raise the character limit, and it needs to be checked on your own server. The visibility levels are public, "quiet" public, followers-only and a private mention.
What is forbidden is decided by the server. The common minimum for the catalogue is set by the Server Covenant: active moderation against racism, sexism, homophobia and transphobia; daily backups; more than one person with access in case of an emergency; and "a commitment to give users at least 3 months' notice in case of shutting down".
How to grow
There is no algorithmic feed: the home page states that the timeline is "curated and created by you". Growth comes through follows, hashtags and boosts.
Search is limited by design. The documentation on the network says that you can search by hashtags, links and names, while full-text search is something "administrators can install additionally" — on some servers it is not there. The same page says that there is no "global shared state across all servers": your server shows only those posts it has learned about.
There is no advertising, neither as a product nor as an ad account. No built-in statistics for authors is described in the user documentation we opened. A profile can be included in the profile directory.
Path to monetization
Mastodon does not pay authors, and there can be no single payout programme here: the network consists of independent servers, each with its own economics. Neither a partner programme, nor advertising revenue share, nor a subscription to an author is described on the project pages we opened.
The project itself lives on donations: the "About" section recounts that "initial support through Patreon allowed Eugen to work on the project full-time after graduating". Individual servers may collect money for their upkeep, but the terms differ for each — that is something to find out from the administrator of the particular server.
Tools and automation
Every server has an API, and it is the same one. The API section describes a REST interface, OAuth authorisation with scopes, application registration and a streaming interface for real time.
The limits are published. According to the rate limits page, "all endpoints and methods can be called 300 times per 5 minutes" — both per account and per IP. Media upload POST /api/v1/media — 30 calls per 30 minutes; deleting statuses and undoing boosts — 30 per 30 minutes in total; creating accounts POST /api/v1/accounts — 5 per 30 minutes from one IP. What is left arrives in the X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset headers.
Moving house is worth knowing about separately. The documentation on moving explains: followers are carried over by the Move activity, but "your posts will not be moved due to technical limitations", while follows, blocks and bookmarks are transferred by hand through a CSV export. There is a "30-day cooldown period during which you cannot migrate again".
Limits and rules
The main limitation is organisational: the rules that apply to you are the ones written by the administrator of your server, and the legal framework is distributed too — every server has its own operator and its own jurisdiction. The German connection relates to the software developer (Berlin, according to the "About" section), not to every server in the network.
The protection instruments are described in the moderation documentation: muting (with which "the user has no way of knowing that they have been muted"), blocking, blocking an entire domain, keyword filters and reports to moderators with the option of forwarding them to a remote server.
Who it's for
Mastodon suits projects and communities that need a platform without advertising and without a recommendation feed, with full API access and the ability to leave together with your followers. It sits well with open, technical and professional subjects.
It does not suit those counting on reach "from the algorithm", an ad account and payouts from the platform. And you need to be ready for the fact that some of the terms — the character limit, full-text search, the rules — depend on the server.
Tools for this platform
The list is built from the tools' own facts: every line is a tool's statement that it supports the platform, with the source named. A tool missing from the list only means we have no such statement.
Scheduling and publishing:
- Buffer — states support; source, checked 2026-07-28
- CoSchedule — states support; source, checked 2026-07-28
- Publer — publishing; source, checked 2026-07-28
- Zoho Social — states support; source, checked 2026-07-28
Automation:
- Activepieces — states support; source, checked 2026-07-28
- IFTTT — states support; source, checked 2026-07-28
Verified data
The checked data this deep dive rests on.
About the platform
the platform describes itself as follows: «Learn more about Mastodon, the radically different, free and open-source decentralized social media platform.»
Self-description: this is the platform's claim about itself, not an independent assessment
source, checked 2026-07-28
the developer is a non-profit structure; the project was incorporated as a gGmbH in 2021 and later lost its non-profit status in Germany; in 2025 a transfer to a new foundation began
There is also Mastodon, Inc. with 501(c)(3) status in the US
source, checked 2026-07-28
the address of the German legal entity is Berlin; the project was created by Eugen Rochko in 2016
The German connection relates to the software developer, not to every server
source, checked 2026-07-28
each server is run by an independent organisation or person and may differ in its moderation policies
The direct wording of the server selection page
source, checked 2026-07-28
Getting started
three registration modes: open, by invitation and with moderator approval
The user documentation
source, checked 2026-07-28
Account and access
the profile has 4 rows of metadata; the display name is up to 30 characters by default, the bio up to 500 characters by default
Default values, which a server may change
source, checked 2026-07-28
verification works through a link with the rel="me" attribute leading back to the profile; there is no paid tick
The user documentation
source, checked 2026-07-28
when moving, followers are carried over by the Move activity, posts are not; a 30-day period applies before the next migration
Follows and blocks are transferred by hand through CSV
source, checked 2026-07-28
What you can publish
Images. "Images (PNG, JPG, HEIF, WEBP, AVIF) up to 16MB. Images will be downscaled to 8.3 megapixels (enough for a 3840x2160 image). Up to 4 images can be attached, per post". An animated GIF is counted separately: "Animated GIFs (GIFV) up to 16MB are converted to soundless MP4s. GIF dimensions must be less than 1MP (1280x720)... Only one animated GIF can be attached, per post. Static GIF files have the same limits applied to them as animated GIF files". The same limits in machine form: "image_size_limit: 16777216" bytes, "image_matrix_limit: 33177600" pixels, "max_media_attachments: 4"
the platform is not a single service but a program for individual instances, and almost all the numbers are configured by the owner of the instance: the documentation names them as values by default, while the values in force are given out by the instance in the configuration field in the response of the instance method; joinmastodon.org and docs.joinmastodon.org have no robots.txt, crawling is not disallowed; 16 MB and 4 attachments are values by default, the instance has the right to change them; the machine values — https://docs.joinmastodon.org/entities/Instance/
source, checked 2026-08-04
Audio is an independent kind of attachment: "Audio (MP3, OGG, WAV, FLAC, OPUS, AAC, M4A, 3GP) up to 99MB. Audio will be transcoded to MP3 using V2 VBR (roughly 192kbps). Only one audio file can be attached, per post". The list of accepted types in the response of the instance method is wider: audio/wave, audio/wav, audio/x-wav, audio/x-pn-wave, audio/vnd.wave, audio/ogg, audio/vorbis, audio/mpeg, audio/mp3, audio/webm, audio/flac, audio/aac, audio/m4a, audio/x-m4a, audio/mp4, audio/3gpp
the platform is not a single service but a program for individual instances, and almost all the numbers are configured by the owner of the instance: the documentation names them as values by default, while the values in force are given out by the instance in the configuration field in the response of the instance method; joinmastodon.org and docs.joinmastodon.org have no robots.txt, crawling is not disallowed; the limit on the file size of audio is the same as for video — 99 MB; the types — https://docs.joinmastodon.org/entities/Instance/
source, checked 2026-08-04
Video. "Videos (MP4, M4V, MOV, WebM) up to 99MB. Video will be transcoded to H.264 MP4 with a maximum bitrate of 1300kbps and framerate of 120fps. Only one video can be attached, per post". In machine form: "video_size_limit: 103809024" bytes, "video_frame_rate_limit: 120", "video_matrix_limit: 8294400" pixels. The list of accepted types at the instance method is wider than in the guide: "video/webm", "video/mp4", "video/quicktime", "video/ogg", "video/x-ms-asf"
the platform is not a single service but a program for individual instances, and almost all the numbers are configured by the owner of the instance: the documentation names them as values by default, while the values in force are given out by the instance in the configuration field in the response of the instance method; joinmastodon.org and docs.joinmastodon.org have no robots.txt, crawling is not disallowed; the list of formats in the guide for the user (MP4, M4V, MOV, WebM) and the list of types in the example response of the instance method (video/ogg and video/x-ms-asf are added) do not coincide; the machine values — https://docs.joinmastodon.org/entities/Instance/
source, checked 2026-08-04
The file size of an attachment: an image and a GIF — "up to 16MB", video and audio — "up to 99MB"; in machine form "image_size_limit: 16777216" and "video_size_limit: 103809024". The number of attachments in a post: "max_media_attachments: 4", and at the same time an animated GIF, a video and audio are one per post. The rate of calls is set separately by counter: "Per account: All endpoints and methods can be called 300 times within 5 minutes", "Uploading media POST /api/v1/media can be called 30 times within 30 minutes", "Deleting statuses... 30 times within 30 minutes"; "Per IP: All endpoints and methods can be called 300 times within 5 minutes", "Creating accounts POST /api/v1/accounts can be called 5 times within 30 minutes"
the platform is not a single service but a program for individual instances, and almost all the numbers are configured by the owner of the instance: the documentation names them as values by default, while the values in force are given out by the instance in the configuration field in the response of the instance method; joinmastodon.org and docs.joinmastodon.org have no robots.txt, crawling is not disallowed; all the numbers listed are values by default for an instance, the owner of the instance has the right to set others, and therefore the network has no single limit; the file sizes — https://docs.joinmastodon.org/user/posting/ ; the page about rate limits is marked "Last updated November 20, 2022"
source, checked 2026-08-04
Text length. Sources diverge: "The main body of each status update can be composed using the text field. The default character limit is 500 characters" — 500 characters are named as the value by default, not as a hard limit. Links are counted at a constant length: "All links are counted as 23 characters, no matter how long they actually are", and for a mention "Only the username part will count against your character limit – the domain is not counted". Other fields are set separately: in the response of the instance method "max_characters: 500", "characters_reserved_per_url: 23", the profile name "max_display_name_lenth: 30", the profile description "max_note_length: 500", the profile field "profile_field_name_limit: 255" and "profile_field_value_limit: 255", the caption to an attachment "description_limit: 1500"
the platform is not a single service but a program for individual instances, and almost all the numbers are configured by the owner of the instance: the documentation names them as values by default, while the values in force are given out by the instance in the configuration field in the response of the instance method; joinmastodon.org and docs.joinmastodon.org have no robots.txt, crawling is not disallowed; the source contradicts itself about the length of a poll option: the guide for the user says "Each choice can be up to 25 characters", while the example response of the instance method shows "max_characters_per_option: 50"; the numbers of the fields — https://docs.joinmastodon.org/entities/Instance/
source, checked 2026-08-04
Promotion
there is no algorithmic feed: the platform states that the timeline is «curated and created by you»
The project's claim about itself
source, checked 2026-07-28
search works by hashtags, links and names; full-text search is installed by administrators additionally
On some servers there is no full-text search
source, checked 2026-07-28
Advertising
the platform states: «We will never show you ads or push profiles at you»
The project's claim about itself
source, checked 2026-07-28
Limits and restrictions
the post limit is 500 characters by default; the domain part of mentions is not counted towards it
A server administrator can change the value
source, checked 2026-07-28
up to 4 images, or one GIF animation or video, or one audio file per post
The user documentation
source, checked 2026-07-28
images (PNG, JPG, HEIF, WEBP, AVIF) and GIFV — up to 16 MB; video (MP4, M4V, MOV, WebM) and audio — up to 99 MB
Default values
source, checked 2026-07-28
a poll has up to 4 options of 25 characters each, running from 5 minutes to 7 days
The user documentation
source, checked 2026-07-28
all API methods — 300 calls per 5 minutes (per account and per IP); media upload — 30 per 30 minutes; account creation — 5 per 30 minutes from one IP
The official rate limits page
source, checked 2026-07-28
Restrictions
the Server Covenant requires servers in the catalogue to have: moderation against racism, sexism, homophobia and transphobia; daily backups; more than one administrator; at least 3 months' notice of a shutdown
The only common set of requirements for the catalogue
source, checked 2026-07-28
a user has muting, blocking, domain blocking, keyword filters and reports with forwarding to a remote server available
The user documentation
source, checked 2026-07-28
API access
a REST API with OAuth authorisation, application registration and a streaming interface; it is the same on all servers
The official API documentation
source, checked 2026-07-28
Languages
the interface language of the home page: en
The language is taken from the markup attribute, the versions from hreflang
source, checked 2026-07-28
a user can show only posts in selected detected languages in the public timelines
User preferences
source, checked 2026-07-28
Catalogue section: all similar See also: catalogue index · region: Western Europe · scheduler comparison · find by situation · platform restrictions