Can an edge function solve case-sensitive redirects?

I understand that redirects are case-sensitive because URLs are case-sensitive by design, and the general guidance offered is to create multiple redirects to support additional cases.

In our case, we cannot create variants of the redirects for mixed-cases because the redirects are sourced from a CMS and represent marketing / short URL redirects, rather than API rewrites that we have control over how they are used. The permutations would be too many. However, a situation where a user types in a URL in mixed case and gets a 404 rather than being redirected is not ideal.

Are Edge Handlers a potential solution to this? Could they be used to rewrite the incoming URL into lowercase before it is then processed? Or perhaps isntead issuing a 301 response to the lowercase variant of a URL, if it is detected that it is in mixed case? We would just apply this logic to the path and not the query.

Are there other solutions that can be done within Netlify?

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Unfortunately this post did not provoke a response, but I can say that in our case we were able to handle this situation with a function. I’ll provide this information in case it helps someone else trying to solve this problem.

First, the function is set as a fallback redirect:

	from = '/*'
	to = "/.netlify/functions/redirects"
	status = 200
	force = false

As part of our build we read the 404 file content and then store this for the function, along with a collection of all of the redirects for matching. During execution, the function will match the given path against the known redirects and return a 301 if one is found. If no match is found, the function will instead return a 404 status, along with the content out of the 404 page.

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That’s awesome, glad you found a fix! A function is a really good solution since you can use it to check urls and redirect appropriately. Edge handlers would be a smidge faster since it runs alongside the content at the CDN level and doesn’t require a trip to the origin, but this is a perfectly cromulent solution :slight_smile:

We are implementing something almost identical to what you are describing.
Our lists of redirects approaches 10,000, and we did not want to impede performance of _redirects file itself.
Only catching unmatched files/pages on the back-end won’t impact regular traffic then.

do keep us posted on how this works out, @moop-moop !