HTTP 428 Precondition Required Error: Meaning & Fix
The HTTP 428 Precondition Required error means a required precondition header, like If-Match, is missing. In web scraping, include such headers to meet server requirements and ensure data consistency.
What causes the error?
Missing If-Match or If-Unmodified-Since header in the request.
Incorrect or outdated ETag in If-Match header.
Failure to include a required version identifier in the request headers.
Request headers lacking timestamp or sequence information required for conditional requests.
# Request example curl -X PUT https://sandbox.oxylabs.io/ -H 'Accept: text/html' -H 'Accept-Encoding: compress' -H 'User-Agent: Chrome/91.0.4472.124'
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Common error fixes
Verify the status of the resource and ensure it is not locked by another process or user.
Check the server's configuration settings to ensure that access permissions and resource locks are correctly set.
Contact the administrator to unlock the resource if you do not have the necessary permissions.
Review and resolve any conflicts or dependencies that might be causing the resource to be locked.
# Response example HTTP/1.1 428 Precondition Required Content-Type: text/html Content-Length: 49 <html><body><h1>428 Precondition Required</h1></body></html>
