ForHosting KIT · Developer Utilities

IPv4-mapped IPv6 converter

Dual-stack networks, socket libraries, and certification labs constantly need the two classic embeddings that put a thirty-two-bit IPv4 address inside a one-hundred-twenty-eight-bit IPv6 address: the IPv4-mapped form with a double-colon ffff prefix, and the historical IPv4-compatible form with a pure double-colon ninety-six-bit zero prefix.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Operators paste a dotted quad and want every common literal at once; reverse engineers receive ::ffff:c000:201 in a log and need the embedded IPv4 back without hand-counting hextets. This IPv4-mapped IPv6 converter accepts a plain IPv4 address or an IPv4-mapped or IPv4-compatible IPv6 literal, normalizes the four octets, and returns both mixed-dotted and pure-hex presentations for mapped and compatible forms plus the recovered IPv4 string. The same pure logic powers the free browser widget and the API path, so homework oracles, dual-stack config generators, and production edge workers never disagree on whether 192.0.2.1 maps to ::ffff:192.0.2.1 or to ::ffff:c000:201.

How to use it

Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.

Check your inputs

Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.

Use it again or automate it

Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.

What you can do with it

Get an answer now

Enter one set of values and see the result without building a spreadsheet or script.

Compare scenarios

Change one value at a time and rerun the calculation to understand what affects the result.

Automate repeated work

Use the API when the same calculation needs to run inside your product or workflow.

FAQ

How do I use this capability?

Complete the fields above and run it on this page. The form highlights anything that needs attention.

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/dev/ipv4-mapped-ipv6

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/dev/ipv4-mapped-ipv6 \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"address":"192.0.2.1"}'

const res = await fetch("https://api.kit.forhosting.com/dev/ipv4-mapped-ipv6", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "address": "192.0.2.1"
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/dev/ipv4-mapped-ipv6",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "address": "192.0.2.1"
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/dev/ipv4-mapped-ipv6", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"address":"192.0.2.1"}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"address":"192.0.2.1"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/dev/ipv4-mapped-ipv6", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "address": "192.0.2.1"
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "dev.ipv4_mapped_ipv6",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Read the full KIT documentation →