diff --git a/src/header/arpa_inet/mod.rs b/src/header/arpa_inet/mod.rs
index e982353f..56806d4a 100644
--- a/src/header/arpa_inet/mod.rs
+++ b/src/header/arpa_inet/mod.rs
@@ -2,6 +2,7 @@
 //!
 //! See <https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/arpa_inet.h.html>.
 
+use alloc::{string::String, vec::Vec};
 use core::{
     ptr, slice,
     str::{self, FromStr},
@@ -13,8 +14,8 @@ use crate::{
         bits_arpainet::ntohl,
         bits_socklen_t::socklen_t,
         errno::{EAFNOSUPPORT, ENOSPC},
-        netinet_in::{INADDR_NONE, in_addr, in_addr_t},
-        sys_socket::constants::AF_INET,
+        netinet_in::{INADDR_NONE, INET6_ADDRSTRLEN, in6_addr, in_addr, in_addr_t},
+        sys_socket::constants::{AF_INET, AF_INET6},
     },
     platform::{
         self,
@@ -181,34 +182,111 @@ pub unsafe extern "C" fn inet_ntop(
     dst: *mut c_char,
     size: socklen_t,
 ) -> *const c_char {
-    if af != AF_INET {
-        platform::ERRNO.set(EAFNOSUPPORT);
-        ptr::null()
-    } else if size < 16 {
-        platform::ERRNO.set(ENOSPC);
-        ptr::null()
-    } else {
-        let s_addr = unsafe {
-            slice::from_raw_parts(
-                ptr::from_ref(&(*(src.cast::<in_addr>())).s_addr).cast::<u8>(),
-                4,
-            )
-        };
-        let addr = format!("{}.{}.{}.{}\0", s_addr[0], s_addr[1], s_addr[2], s_addr[3]);
+    if af == AF_INET6 {
+        if size < INET6_ADDRSTRLEN as socklen_t {
+            platform::ERRNO.set(ENOSPC);
+            return ptr::null();
+        }
+        let s6_addr = unsafe { &(*(src.cast::<in6_addr>())).s6_addr };
+        let output = inet_ntop6(s6_addr);
+        let bytes = output.as_bytes();
         unsafe {
-            ptr::copy(addr.as_ptr().cast::<c_char>(), dst, addr.len());
+            ptr::copy(bytes.as_ptr().cast::<c_char>(), dst, bytes.len());
+            *dst.add(bytes.len()) = 0;
         }
         dst
+    } else if af == AF_INET {
+        if size < 16 {
+            platform::ERRNO.set(ENOSPC);
+            ptr::null()
+        } else {
+            let s_addr = unsafe {
+                slice::from_raw_parts(
+                    ptr::from_ref(&(*(src.cast::<in_addr>())).s_addr).cast::<u8>(),
+                    4,
+                )
+            };
+            let addr = format!("{}.{}.{}.{}\0", s_addr[0], s_addr[1], s_addr[2], s_addr[3]);
+            unsafe {
+                ptr::copy(addr.as_ptr().cast::<c_char>(), dst, addr.len());
+            }
+            dst
+        }
+    } else {
+        platform::ERRNO.set(EAFNOSUPPORT);
+        ptr::null()
+    }
+}
+
+fn inet_ntop6(addr: &[u8; 16]) -> String {
+    let groups: [u16; 8] = core::array::from_fn(|i| {
+        u16::from_be_bytes([addr[i * 2], addr[i * 2 + 1]])
+    });
+
+    let mut best_start = 8usize;
+    let mut best_len = 1usize;
+    let mut cur_start = 8usize;
+    let mut cur_len = 0usize;
+
+    for i in 0..8 {
+        if groups[i] == 0 {
+            if cur_len == 0 {
+                cur_start = i;
+            }
+            cur_len += 1;
+        } else {
+            if cur_len > best_len {
+                best_start = cur_start;
+                best_len = cur_len;
+            }
+            cur_len = 0;
+        }
+    }
+    if cur_len > best_len {
+        best_start = cur_start;
+        best_len = cur_len;
+    }
+
+    let mut parts = Vec::new();
+    let mut i = 0usize;
+    while i < 8 {
+        if i == best_start && best_len > 1 {
+            if i == 0 {
+                parts.push(String::new());
+            }
+            if i + best_len == 8 {
+                parts.push(String::new());
+            }
+            i += best_len;
+        } else {
+            parts.push(format!("{:x}", groups[i]));
+            i += 1;
+        }
+    }
+
+    if best_len == 8 {
+        return String::from("::");
     }
+
+    parts.join(":")
 }
 
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/inet_ntop.html>.
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn inet_pton(af: c_int, src: *const c_char, dst: *mut c_void) -> c_int {
-    if af != AF_INET {
-        platform::ERRNO.set(EAFNOSUPPORT);
-        -1
-    } else {
+    if af == AF_INET6 {
+        let src_cstr = unsafe { CStr::from_ptr(src) };
+        let src_str = match src_cstr.to_str() {
+            Ok(s) => s,
+            Err(_) => return 0,
+        };
+        let out = unsafe { &mut *(dst.cast::<in6_addr>()) };
+        if inet_pton6(src_str, &mut out.s6_addr) {
+            1
+        } else {
+            0
+        }
+    } else if af == AF_INET {
         let s_addr = unsafe {
             slice::from_raw_parts_mut(
                 ptr::from_mut(&mut (*dst.cast::<in_addr>()).s_addr).cast::<u8>(),
@@ -233,5 +311,137 @@ pub unsafe extern "C" fn inet_pton(af: c_int, src: *const c_char, dst: *mut c_vo
         } else {
             0
         }
+    } else {
+        platform::ERRNO.set(EAFNOSUPPORT);
+        -1
+    }
+}
+
+fn inet_pton6(src: &str, dst: &mut [u8; 16]) -> bool {
+    dst.fill(0);
+
+    let double_colon_pos = src.find("::");
+    let second_double = if let Some(pos) = double_colon_pos {
+        src[pos + 2..].find("::").map(|p| p + pos + 2)
+    } else {
+        None
+    };
+    if second_double.is_some() {
+        return false;
+    }
+
+    let (left_str, right_str) = match double_colon_pos {
+        Some(pos) => (&src[..pos], &src[pos + 2..]),
+        None => (src, ""),
+    };
+
+    let left_groups: Vec<&str> = if left_str.is_empty() {
+        Vec::new()
+    } else {
+        left_str.split(':').collect()
+    };
+    let right_groups: Vec<&str> = if right_str.is_empty() {
+        Vec::new()
+    } else {
+        right_str.split(':').collect()
+    };
+
+    let right_has_ipv4 = right_groups.last().is_some_and(|g| g.contains('.'));
+    let mut left_count = left_groups.len();
+    let mut right_count = right_groups.len();
+    if right_has_ipv4 {
+        right_count -= 1;
+        left_count += 1;
+    }
+
+    let gap = 8 - left_count - right_count;
+    if double_colon_pos.is_none() && gap != 0 {
+        return false;
+    }
+    if double_colon_pos.is_some() && gap < 0 {
+        return false;
+    }
+    if double_colon_pos.is_none() && left_groups.len() + right_groups.len() != 8 {
+        return false;
+    }
+
+    let mut idx = 0usize;
+
+    for group in &left_groups {
+        if idx >= 16 {
+            return false;
+        }
+        let val = match parse_hex_group(group) {
+            Some(v) => v,
+            None => return false,
+        };
+        dst[idx] = (val >> 8) as u8;
+        dst[idx + 1] = val as u8;
+        idx += 2;
+    }
+
+    if double_colon_pos.is_some() {
+        for _ in 0..gap {
+            if idx >= 16 {
+                return false;
+            }
+            dst[idx] = 0;
+            dst[idx + 1] = 0;
+            idx += 2;
+        }
+    }
+
+    let right_hex_count = if right_has_ipv4 {
+        right_groups.len().saturating_sub(1)
+    } else {
+        right_groups.len()
+    };
+
+    for group in &right_groups[..right_hex_count] {
+        if idx >= 16 {
+            return false;
+        }
+        let val = match parse_hex_group(group) {
+            Some(v) => v,
+            None => return false,
+        };
+        dst[idx] = (val >> 8) as u8;
+        dst[idx + 1] = val as u8;
+        idx += 2;
+    }
+
+    if right_has_ipv4 {
+        if idx != 12 {
+            return false;
+        }
+        let ipv4_str = right_groups[right_groups.len() - 1];
+        let parts: Vec<&str> = ipv4_str.split('.').collect();
+        if parts.len() != 4 {
+            return false;
+        }
+        for (i, part) in parts.iter().enumerate() {
+            match u8::from_str(part) {
+                Ok(v) => dst[12 + i] = v,
+                Err(_) => return false,
+            }
+        }
+        idx += 4;
+    }
+
+    idx == 16
+}
+
+fn parse_hex_group(s: &str) -> Option<u16> {
+    if s.is_empty() || s.len() > 4 {
+        return None;
+    }
+    let mut val: u16 = 0;
+    for c in s.chars() {
+        val = val.checked_mul(16)?;
+        match c.to_digit(16) {
+            Some(d) => val = val.checked_add(d as u16)?,
+            None => return None,
+        }
     }
+    Some(val)
 }