The Access-Control-Allow-Headers response header is used in response to a preflight request which includes the Access-Control-Request-Headers to indicate which HTTP headers can be used during the actual request. This header is required if the request has an Access-Control-Request-Headers header
| Websites using header Access-Control-Allow-Headers | 546,317 |
| Percentage of websites that use Access-Control-Allow-Headers header | 0.95% |
| Total discovered header values | More than 10,000 |
| Header uses directives | Yes |
| Header values are unique or random | No |
| Most popular in the country |  United States |
| Directive | Share | Websites count | Unique Values |
|---|---|---|---|
| content-type | 80.47% | 439,606 | 2 |
| x-requested-with | 49.38% | 269,785 | 2 |
| authorization | 42.38% | 231,531 | 2 |
| origin | 31.31% | 171,053 | 1 |
| accept | 28.17% | 153,924 | 1 |
| cache-control | 13.24% | 72,328 | 1 |
| user-agent | 12.32% | 67,308 | 1 |
| if-modified-since | 11.21% | 61,218 | 1 |
| * | 10.74% | 58,697 | 1 |
| dnt | 10.03% | 54,774 | 1 |
| keep-alive | 7.48% | 40,840 | 1 |
| x-customheader | 4.34% | 23,683 | 1 |
| x-accept-charset | 2.01% | 10,957 | 1 |
| client-security-token | 1.49% | 8,115 | 1 |
| soapaction | 0.65% | 3,564 | 1 |
| typeform-version | 0.37% | 2,006 | 1 |
| x-typeform-key | 0.37% | 2,006 | 1 |
| access_token | less than 0.1% | 319 | 1 |
| Domain | Country | Rank | Contacts |
|---|---|---|---|
| United States | 31 | ||
| United States | 34 | ||
| United States | 64 | ||
| United States | 77 | ||
| United States | 96 | ||
| United States | 131 |
| Header value | Value prevalence |
|---|---|
| Content-Type, Authorization | 13% |
| * | 10% |
| content-type | 7% |
| origin, x-requested-with, content-type | 7% |
| Origin, X-Requested-With, Content-Type, Accept | 5% |
| X-Requested-With | 2% |
| Content-Type, Authorization, X-Requested-With | 2% |
| X-Accept-Charset,X-Accept,Content-Type | 1% |
| Origin, X-Requested-With, Content-Type, Accept, Authorization | 1% |
| accept, x-request, x-requested-with | 1% |
| DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization | 1% |
| DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range | 1% |
| x-sap-service | 1% |
| DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type | 1% |
| Content-Type,Accept | 1% |
| x-requested-with,content-type | 1% |
| Origin,Content-Type,Accept,User-Agent,Cookie,Authorization,X-Auth-Token,X-Requested-With | 0% |
| Authorization, Content-Type | 0% |
| x-requested-with, Content-Type, origin, authorization, accept, client-security-token | 0% |
| Accept, Authorization, Content-Type | 0% |
