CURLINFO\_HEADER\_SIZE(3) Library Functions Manual CURLINFO\_HEADER\_SIZE(3)

# [NAME](#NAME)

CURLINFO\_HEADER\_SIZE - size of response headers

# [SYNOPSIS](#SYNOPSIS)

```
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_HEADER_SIZE, long *sizep);
```

# [DESCRIPTION](#DESCRIPTION)

Pass a pointer to a long to receive the total size of all the headers received, represented in HTTP/1-style header format. Measured in number of bytes.

The total includes the size of any received headers suppressed by [*CURLOPT\_SUPPRESS\_CONNECT\_HEADERS(3)*](/man/os/curl/CURLOPT_SUPPRESS_CONNECT_HEADERS.3).

The number of bytes transferred over the wire (or to the TLS backend) is different when using HTTP/2 or greater.

# [PROTOCOLS](#PROTOCOLS)

This functionality affects all supported protocols

# [EXAMPLE](#EXAMPLE)

```
int main(void)
{


  CURL *curl = curl_easy_init();


  if(curl) {


    CURLcode result;


    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");


    result = curl_easy_perform(curl);


    if(result == CURLE_OK) {


      long size;


      result = curl_easy_getinfo(curl, CURLINFO_HEADER_SIZE, &size);


      if(result == CURLE_OK)


        printf("Header size: %ld bytes\n", size);


    }


    curl_easy_cleanup(curl);


  }
}
```

# [AVAILABILITY](#AVAILABILITY)

Added in curl 7.4.1

# [RETURN VALUE](#RETURN_VALUE)

[*curl\_easy\_getinfo(3)*](/man/os/curl/curl_easy_getinfo.3) returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see [*libcurl-errors(3)*](/man/os/curl/libcurl-errors.3).

# [SEE ALSO](#SEE_ALSO)

[**CURLINFO\_REQUEST\_SIZE**(3)](/man/os/curl/CURLINFO_REQUEST_SIZE.3), [**CURLINFO\_SIZE\_DOWNLOAD**(3)](/man/os/curl/CURLINFO_SIZE_DOWNLOAD.3), [**curl\_easy\_getinfo**(3)](/man/os/curl/curl_easy_getinfo.3), [**curl\_easy\_setopt**(3)](/man/os/curl/curl_easy_setopt.3)

2026-09-24 libcurl

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Document: CURLINFO_HEADER_SIZE(3) from curl 8.22.0-r3 (Chainguard OS)
Source: https://github.com/curl/curl.git