Azure Static Web App returns 403 to Facebook Sharing Debugger, but curl with facebookexternalhit returns 200

Question

Azure Static Web App returns 403 to Facebook Sharing Debugger, but curl with facebookexternalhit returns 200

John Harris 0

I've created a static web app and got it ready for live.

I've added og-image and other og tags so when the app is shared it has what I've provided.

Google has indexed the page and bing and LinkedIn uses the og image when shared.

Ive been trying to use the facebook debugger to scrape the page and it keeps coming up with a 403.

When i click "See exactly what our scraper sees for your URL" i get : The document returned no data.

My robots has:

User-agent: *

Allow: /

and when i use curl and "facebookexternalhit/1.1" it returns 200

Im thinking azure is blocking the facebook crawler before my app makes any decision about it how can i fix this? Surely this must happen to other people

How can I see or control whatever layer is returning 403 to Facebook’s crawler on Azure Static Web Apps, given the app itself returns 200 for the same user agent?

Hosting: Azure Static Web Apps Framework: React/Vite

Custom domain: https://edgely.co.uk

Free/Standard plan tested: both

staticwebapp.config.json has no auth restrictions robots.txt allows all

LinkedIn Post Inspector works

Google indexing works

Direct og-image URL works

curl with facebookexternalhit returns 200

Facebook Sharing Debugger returns 403 / document returned no data

Golla Venkata Pavani 7,535 Reputation points Microsoft External Staff Moderator

2026-04-30T17:16:04.4366667+00:00
Hi @John Harris

Thank you for reaching us regarding the issue.

The 403 Forbidden you see in the Facebook Sharing Debugger (while curl with the facebookexternalhit user-agent returns 200) is not coming from your React/Vite app, robots.txt, or staticwebapp.config.json. All requests to Azure Static Web Apps are first processed by the platform’s global edge infrastructure (powered by Azure Front Door technology). This front-end layer applies traffic filtering and protection mechanisms. It can return a 403 before the request ever reaches your static content — especially when the request originates from Meta’s datacenter IPs, even if the User-Agent matches.

Your local curl tests succeed because they come from a different IP context. Other crawlers (Google, Bing, LinkedIn) are generally allowed without issue.

Recommendations:

Test the default Azure domain
Try the Facebook Sharing Debugger on your https://yourapp.azurestaticapps.net/... URL instead of edgely.co.uk. If it works on the default domain but fails on your custom domain, the issue is likely related to custom domain validation.

Re-validate your custom domain
Go to your Static Web App in the Azure Portal > Custom domains. Ensure edgely.co.uk shows as Validated / Ready. If it’s pending or failed, remove and re-add the domain, then confirm your CNAME record has fully propagated.
Reference : https://learn.microsoft.com/en-us/azure/static-web-apps/custom-domain

Long-Term Solution:

Azure Static Web Apps (Free or Standard plan) does not provide direct visibility or configuration options for the edge-layer bot filtering.

If you need reliable access for Facebook’s crawler (and similar services), the recommended approach is to place your app behind Azure Front Door. This gives you:

Visibility into blocked requests

Custom WAF and bot management rules

Ability to allowlist Meta’s user-agents or ASN (32934)

Better control over headers and caching

Reference: https://learn.microsoft.com/en-us/azure/static-web-apps/custom-domain
https://learn.microsoft.com/en-us/azure/static-web-apps/front-door-manual?tabs=azure-portal&pivots=swa-afd-enterprise-grade-edge

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.
Golla Venkata Pavani 7,535 Reputation points Microsoft External Staff Moderator

2026-05-01T18:08:08.4+00:00

Hi @John Harris

I'm just reaching out to see if your issue has been resolved or if you've had a chance to review my previous comment?

Your answer

Golla Venkata Pavani 7,535 Reputation points Microsoft External Staff Moderator

2026-05-01T18:08:08.4+00:00

Hi @John Harris

I'm just reaching out to see if your issue has been resolved or if you've had a chance to review my previous comment?