Ajax

Why Your Ajax Requests “Randomly” Fail in Production

- - ErcanOPAK

Locally works.
Production fails.

Cause
Preflight CORS requests.

What happens
Browser sends:

OPTIONS /api/data

Before:

POST /api/data

If server doesn’t handle OPTIONS → fail.

Minimal fix (ASP.NET example)

app.UseCors(builder =>
  builder.AllowAnyOrigin()
         .AllowAnyMethod()
         .AllowAnyHeader());

Why this matters
Ajax failures are often network policy, not JS bugs.

Related posts:

Abort Fetch Requests to Prevent UI Race Conditions

AJAX — 204 Responses Break JSON Parsing

AJAX: Use Fetch with Signal to Cancel Requests When User Navigates Away

Post Views: 5

Leave a Reply

Your email address will not be published. Required fields are marked *