# `react-doctor/no-sync-xhr`

Synchronous XMLHttpRequest

- **Category:** Performance
- **Severity:** warn
- **Source:** oxlint-plugin-react-doctor
- **Framework:** global
- **Enabled when:** always

## Validation prompt

Use this to decide whether a fired diagnostic is real or a false positive.

Confirm the reported code matches Synchronous XMLHttpRequest. Check the framework context and diagnostic message before suppressing it.

## Fix prompt

Use this once validation confirms the diagnostic is real.

Never open an XMLHttpRequest synchronously (`async` = `false`). It blocks the main thread. Use `fetch()` or pass `true` and handle the response asynchronously.