# convertIPv6BinaryToString

**Kind:** Function

**Source:** [`src/utils/ipaddr.ts`](https://github.com/honojs/hono/blob/main/src/utils/ipaddr.ts#L327)

**Part of:** [Utils](subsystem-src-utils)

Convert a binary representation of an IPv6 address to a string.

`convertIPv6BinaryToString` converts an IPv6 address from its binary representation into a string. Use it at boundaries where binary address data must be displayed, logged, or passed to code that expects an IPv6 string.

## Signature

```ts
function convertIPv6BinaryToString(ipV6: bigint): string
```

## Parameters

| Name | Type |
|---|---|
| `ipV6` | `bigint` |

**Returns:** `string`

## Diagram

```mermaid
graph LR
  A[Binary IPv6 value] --> B[convertIPv6BinaryToString]
  B --> C[IPv6 string]
```

## Usage

```ts
import { convertIPv6BinaryToString } from "./utils/ipaddr";

// Obtain the binary IPv6 value from a network, parser, or storage layer.
declare const binaryIPv6: string;

const ipv6Address = convertIPv6BinaryToString(binaryIPv6);

console.log(ipv6Address);
```

## AI Coding Instructions

- Pass the binary IPv6 value to this function, not an already formatted IPv6 string.
- Keep binary-to-string conversion at input or output boundaries rather than spreading address formatting logic across callers.
- Preserve the binary value unchanged before conversion; changing its order changes the resulting address.
- Use the returned string for display, logging, serialization, or APIs that accept textual IPv6 addresses.

## Used by

1 reference from 1 file. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (1)

- `IPRestrictionRule` — `src/middleware/ip-restriction/index.ts`:38