Mastodon Bio Fields Explained: Full Reference (2026)

TL;DR:
  • Mastodon profile has: display name (30 chars), bio body (500 chars), 4 metadata fields (Label + Content pairs).
  • Metadata fields commonly used for: Website, Newsletter, Pronouns, Location, Languages.
  • Each metadata field can be a verified URL (via rel="me") for green checkmark.

Profile Fields

FieldLimitNotes
Display name30 charactersPublic name; can include emoji
Username (handle)30 charactersHandle within instance
Federated handle~50 characters@[email protected]
Bio body description500 charactersAuto-linked URLs
Profile metadata fields4 entries ?— 255 chars eachLabel + Content pairs
Avatar2 MB image400 ?— 400 px recommended
Header image2 MB image1500 ?— 500 px recommended

Common Metadata Field Uses

LabelContent type
WebsiteURL ??” verifiable via rel="me"
BlogURL
NewsletterURL
GitHubURL or @ handle
PronounsText (e.g., "she/her")
LocationText (e.g., "Berlin")
LanguagesText (e.g., "EN, DE")
Bio linkURL ??” your bio link tool

Bio Body

500 characters supports rich descriptions:

  • Mission line.
  • What you post about.
  • Featured projects / interests.
  • Any additional URLs.

URLs auto-link with https:// prefix.

Verified Metadata Fields

Any metadata URL with rel="me" back-link from the destination becomes verified (green checkmark).

Recommended Field Setup

  1. Field 1: Website / Blog ?†’ primary URL (verified via rel="me").
  2. Field 2: Newsletter / Bio link tool URL.
  3. Field 3: Pronouns or Location.
  4. Field 4: GitHub or alternate social.

Custom Emoji

Mastodon supports custom emoji in display name + bio + metadata. Each instance has its own emoji set. Use :emoji_name: syntax.

Federated Visibility

Your full profile (all fields) is visible to anyone on any Mastodon instance. Bio metadata replicates across federation.


FAQ

How many bio fields does Mastodon have?

4 metadata fields + bio body description.

What's the bio character limit?

500 characters for body. 255 per metadata field. 30 for display name.

Can metadata fields be verified?

Yes ??” any URL with rel="me" back-link.

Can I have more than 4 metadata fields?

4 is the standard limit on most instances.

Are emoji supported in profile?

Yes ??” both Unicode + custom instance emoji via :name: syntax.


Key Takeaways
  • 4 metadata fields + 500-char bio body.
  • Metadata supports verification via rel="me".
  • Display name 30 chars with emoji support.
  • Federated ??” visible across all Mastodon instances.

Verified bio link for Mastodon metadata

UniLink + rel="me" = green checkmark next to your URL on Mastodon.

Try UniLink free ?†’