400 upon logout, redirect URI looks fine, no other clues

I am doing local testing of an Okta integration, with my server running on localhost:9000. I am testing in an Incognito window. Sign-in works fine, however sign-out is resulting in a 400 error. The URL is:


The Okta application has two configured sign-out redirect URIs:

The parameter in the /logout URL decodes to the second redirect URI above. The HTTP response is:


I don’t see this sign-out attempt in the Okta logs, so I’m not sure how to proceed. Suggestions?

Thanks in advance.

Just adding that logout worked okay yesterday, and I don’t think anything changed on my end, though I can’t be 100% sure.

Unless you omitted it in your post, I don’t see an id_token_hint in your /logout request. Our docs do mention some reasons you can encounter errors with /logout and I would focus on id_token_hint to start with.

That looks promising. Thanks for the reference.