Webmentions are a web standard for conversations and interactions between websites. They're a W3C Recommendation that allows websites to notify each other when one site links to another.

The Simple Explanation

Think of Webmentions as @mentions for the entire web. When you mention someone's blog post on your own site, you can send them a notification through a Webmention. This creates a decentralized network of conversations that isn't controlled by any single platform.

How They're Different from Comments

Traditional comment systems are centralized:

• Comments live in a database on the target site
• You don't own your comment data
• If the site goes down, comments disappear
• Often require creating accounts

With Webmentions:

• You write on your own site (you own the content)
• Send a notification to the site you're referencing
• They can display your mention (after verification)
• No account needed on their site

Technical Overview

The Webmention protocol follows these steps:

1. Discovery: Your site finds the Webmention endpoint of the target URL
2. Notification: You send a POST request with your URL and their URL
3. Verification: They fetch your page to confirm the link exists
4. Display: If valid, they can display your mention

Endpoint Discovery

Sites advertise their Webmention endpoint in two ways:

HTML Link Element:

<link rel="webmention" href="https://example.com/webmention" />

HTTP Link Header:

Link: <https://example.com/webmention>; rel="webmention"

Types of Interactions

Webmentions support various interaction types:

• Replies: Responding to someone's post
• Likes: Showing appreciation for content
• Reposts: Sharing content to your audience
• Bookmarks: Saving content for later
• RSVPs: Responding to event invitations
• Mentions: Generic references to a URL

Each type is indicated through microformats markup on your content.

Real-World Example

Sarah writes a blog post about web standards. Tom reads it and writes his own post with additional thoughts, linking to Sarah's article. Tom's publishing system:

1. Detects the link to Sarah's post
2. Discovers Sarah's Webmention endpoint
3. Sends a Webmention notification
4. Sarah's site verifies the mention
5. Sarah's post now shows Tom's response

This creates a distributed conversation where both Sarah and Tom own their content on their own domains.

Getting Started

To participate in the Webmention ecosystem:

As a Receiver

• Add a Webmention endpoint to your site
• Implement verification logic
• Display received mentions

As a Sender

• Detect outbound links in your content
• Discover endpoints on linked URLs
• Send Webmentions when publishing

Many platforms and tools make this easier:

• Webmention.io: Hosted receiver service
• Bridgy: Connects Webmentions with social media
• CMS Plugins: Available for WordPress, Ghost, etc.
• Static Site Tools: Generators like Hugo and Eleventy have Webmention support

Privacy and Control

One key advantage of Webmentions is control:

• You choose which mentions to display
• Verification prevents fake mentions
• You can implement moderation workflows
• Delete or update your mentions anytime

Sites can also implement privacy features like:

• Private mentions (only sender and receiver see them)
• Allowlists for trusted domains
• Manual approval workflows
• Spam filtering

Standards and Specifications

Webmentions are part of a family of IndieWeb standards:

• Webmention Spec: The core protocol
• Microformats: For semantic markup
• Micropub: For publishing
• WebSub: For real-time notifications

Together, these create a comprehensive framework for decentralized web interactions.

Learn More

• Read the official specification
• Join the IndieWeb community
• Test implementations at webmention.rocks
• Explore existing implementations