---
title: Add HEX timestamp to a request header
description: Add a custom header to requests sent to the origin server with the current timestamp in hexadecimal format for debugging, tracking, or custom routing purposes.
image: https://developers.cloudflare.com/core-services-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/rules/llms.txt  
> Use this file to discover all available pages before exploring further. 

[Skip to content](#%5Ftop) 

# Add HEX timestamp to a request header

Add a custom header to requests sent to the origin server with the current timestamp in hexadecimal format.

JavaScript

```
export default {  async fetch(request) {    // Get the current timestamp    const timestamp = Date.now();
    // Convert the timestamp to hexadecimal format    const hexTimestamp = timestamp.toString(16);
    // Clone the request and add the custom header    const modifiedRequest = new Request(request, {      headers: new Headers(request.headers),    });    modifiedRequest.headers.set("X-Hex-Timestamp", hexTimestamp);
    // Log the custom header for debugging    console.log(`X-Hex-Timestamp: ${hexTimestamp}`);
    // Pass the modified request to the origin    const response = await fetch(modifiedRequest);
    return response;  },};
```

```json
{"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/rules/snippets/examples/hex-timestamp/#page","headline":"Add HEX timestamp to a request header · Cloudflare Rules docs","description":"Add a custom header to requests sent to the origin server with the current timestamp in hexadecimal format for debugging, tracking, or custom routing purposes.","url":"https://developers.cloudflare.com/rules/snippets/examples/hex-timestamp/","inLanguage":"en","image":"https://developers.cloudflare.com/core-services-preview.png","dateModified":"2025-10-13","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"},"keywords":["Headers","Request modification"]}
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/rules/","name":"Rules"}},{"@type":"ListItem","position":3,"item":{"@id":"/rules/snippets/","name":"Cloudflare Snippets"}},{"@type":"ListItem","position":4,"item":{"@id":"/rules/snippets/examples/","name":"Snippets examples"}},{"@type":"ListItem","position":5,"item":{"@id":"/rules/snippets/examples/hex-timestamp/","name":"Add HEX timestamp to a request header"}}]}
```