Why Does Pasting a Vimeo URL in Google Sites Auto-Embed (With Fullscreen)?

✅ It’s Called “oEmbed” — and Google Sites Supports It

When you paste a Vimeo link (like https://vimeo.com/123456789) into the Embed by URL field in Google Sites, the system detects it as a recognized media provider through a technology called oEmbed.

What’s oEmbed?

oEmbed is a standardized way that platforms like Vimeo, YouTube, and Twitter offer pre-built embed code when only a URL is provided. It’s like saying:

“If someone pastes this link on their site, auto-generate a safe embed preview with fullscreen, thumbnail, and proper controls.”

🧠 Why Fullscreen Works — Even Without Any Options

When Sites pulls the embed preview from Vimeo:

• It automatically includes the allowfullscreen attribute behind the scenes.
  
  

• The iframe is generated by Vimeo’s own embed service, not by Google.
  
  

• Google Sites doesn’t block fullscreen if Vimeo's embed includes it — and it does.
  
  

So even though Google Sites doesn’t give you a fullscreen toggle in the sidebar UI:

• It respects what the embed source allows
  
  

• And Vimeo allows fullscreen by default
  
  

⚙️ Comparison: Embed by URL vs Embed by Code

Feature

Embed by URL (Vimeo)

Embed by Code (Manual iframe)

Fullscreen Enabled?

✅ Yes

✅ Yes (if coded properly)

Responsive Sizing?

⚠️ Limited

✅ Full control

Customization (autoplay, etc)

❌ Not available

✅ Yes

Easy for beginners?

✅ Very

⚠️ Slight learning curve

🔒 Will It Always Work?

It works as long as:

• The Vimeo video is public or unlisted, and embedding is allowed
  
  

• You're not behind a firewall blocking Vimeo
  
  

• The link is pasted into the "Embed by URL" section, not just a plain text field
  
  

⚠️ If the video is age-restricted, private, or embedding is disabled by the creator,** it may not work or may show an error like “This video is unavailable.”

💡 Bonus: Supported oEmbed Providers in Google Sites

Besides Vimeo, the Embed by URL feature works for:

• YouTube
  
  

• Google Docs, Slides, Sheets
  
  

• SoundCloud
  
  

• Figma
  
  

• Google Maps
  
  

• (And other verified oEmbed platforms)
  
  

They all support fullscreen if the original service does — it’s just that Google Sites doesn’t give you an on/off switch, it just passes it through if allowed.

🧪 Final Answer:

When you paste a Vimeo URL into Google Sites, it auto-embeds because of oEmbed support, and fullscreen works because Vimeo includes that permission in the generated embed, even if Google doesn’t show a toggle.

✨ So yes, it’s automatic — no code needed. Just paste the link, and you’re done.