SPL Token Metadata: Complete Guide

Learn how metadata works for SPL tokens on Solana and how to set it up correctly.

What is SPL Token Metadata?

Token metadata provides human-readable information about your token, including its name, symbol, description, and image. This data is stored on-chain using the Metaplex Token Metadata program.

Metadata Fields

• Name: The full name of your token (e.g., "My Token")
• Symbol: The ticker symbol (e.g., "MTK")
• URI: A link to off-chain JSON metadata containing description, image, etc.
• Seller Fee: Optional royalty percentage (typically 0 for fungible tokens)

Mutable vs Immutable

When creating a token, you can choose whether metadata is mutable:

• Mutable: You can update name, symbol, and URI later
• Immutable: Metadata is permanently locked after creation

Best Practices

• Use high-quality images (recommended: 512x512 PNG)
• Host metadata on permanent storage (Arweave, IPFS)
• Include a clear description of your token's purpose
• Set an external URL for more information