---
name: "CURLINFO_HEADER_SIZE"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLINFO_HEADER_SIZE"
---

# CURLINFO\_HEADER\_SIZE(3)

size of response headers

## NAME

CURLINFO\_HEADER\_SIZE - size of response headers

## SYNOPSIS

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

## 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)](/CURLOPT_SUPPRESS_CONNECT_HEADERS/3.md)*.

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

## PROTOCOLS

This functionality affects all supported protocols

## 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

Added in curl 7.4.1

## RETURN VALUE

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

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

## SEE ALSO

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