GitHub - donlon/cloudflare-error-page: Cloudflare error page generator

Cloudflare Error Page Generator

📢 Update (2025/12/09): All icons used in the error page have been fully redrawn as vector assets. These icons along with the stylesheet are also inlined into a single file of the error page, eliminating any need of hosting additional resources, and ensuring better experience for you and your end users.

What does this project do?

This project creates customized error pages that mimic the well-known Cloudflare error page. You can also embed it into your own website.

Online Editor

Here's an online editor to create customized error pages and example server apps. Try it out here.

Quickstart for Programmers

Python

Install cloudflare-error-page using pip.

# Install from PyPI
pip install cloudflare-error-page

# Or, install the latest version from this repo
pip install git+https://github.com/donlon/cloudflare-error-page.git

Then an error page can be generated using the render function provided by the package. (example.py)

import webbrowser
from cloudflare_error_page import render as render_cf_error_page

# This function renders an error page based on the input parameters
error_page = render_cf_error_page({
    # Browser status is ok
    'browser_status': {
        "status": 'ok',
    },
    # Cloudflare status is error
    'cloudflare_status': {
        "status": 'error',
        "status_text": 'Error',
    },
    # Host status is also ok
    'host_status': {
        "status": 'ok',
        "location": 'example.com',
    },
    # Position of the error indicator, valid options are 'browser', 'cloudflare', and 'host'
    'error_source': 'cloudflare',

    # Texts shown in the bottom of the page
    'what_happened': '<p>There is an internal server error on Cloudflare\'s network.</p>',
    'what_can_i_do': '<p>Please try again in a few minutes.</p>',
})

# Write generated webpage to file
with open('error.html', 'w') as f:
    f.write(error_page)

# Open the generated page in browser
webbrowser.open('error.html')

You can also see live demo here.

A demo server using Flask is also available in flask_demo.py.

JavaScript/NodeJS

Install the cloudflare-error-page package using npm:

npm install cloudflare-error-page

The following example demonstrates how to create an Express application that automatically handles server errors.

import express from 'express';
import { render as render_cf_error_page } from 'cloudflare-error-page';

const app = express();

app.get('/', (req, res) => {
  /* Some code that break prod. Pushed by a new employee recently. */
  let [feature_values, _] = features
    .append_with_names(self.config.feature_names)
    .unwrap();
}

app.use((err, req, res) => {
  /* Handle the error intelligently by using a custom handler */
  res.status(500).send(render_cf_error_page({
    "title": "Internal server error",
    "error_code": "500",
    "what_happened": err.toString(),
    "what_can_i_do": "Please try again in a few minutes.",
  }));
});

app.listen(3000);

(Thanks @junduck for creating the original NodeJS version.)

PHP

More Examples

Catastrophic infrastructure failure

params = {
    "title": "Catastrophic infrastructure failure",
    "more_information": {
        "for": "no information",
    },
    "browser_status": {
        "status": "error",
        "status_text": "Out of Memory",
    },
    "cloudflare_status": {
        "status": "error",
        "location": "Everywhere",
        "status_text": "Error",
    },
    "host_status": {
        "status": "error",
        "location": "example.com",
        "status_text": "On Fire",
    },
    "error_source": "cloudflare",
    "what_happened": "<p>There is a catastrophic failure.</p>",
    "what_can_i_do": "<p>Please try again in a few years.</p>",
}

Demo

Web server is working

params = {
    "title": "Web server is working",
    "error_code": "200",
    "more_information": {
        "hidden": True,
    },
    "browser_status": {
        "status": "ok",
        "status_text": "Seems Working",
    },
    "cloudflare_status": {
        "status": "ok",
        "status_text": "Often Working",
    },
    "host_status": {
        "status": "ok",
        "location": "example.com",
        "status_text": "Almost Working",
    },
    "error_source": "host",
    "what_happened": "<p>This site is still working. And it looks great.</p>",
    "what_can_i_do": "<p>Visit the site before it crashes someday.</p>",
}

Demo

FAQ

How to show real user IP / Cloudflare Ray ID / data center location in the error page so that it looks more realistic?

Ray ID and user IP field in the error page can be set by ray_id and client_ip properties in the params argument passed to the render function. The real Cloudflare Ray ID and the data center location of current request can be extracted from the Cf-Ray request header (e.g. Cf-Ray: 230b030023ae2822-SJC). Detailed description of this header can be found at Cloudflare documentation.

To lookup the city name of the data center corresponding to the three letter code in the header, you can use a location list here

The demo server runs in our website did handle these. Take a look at this file for reference.

Full Parameter Reference

{
    "html_title": "cloudflare.com | 500: Internal server error",
    "title": "Internal server error",
    "error_code": "500",
    "time": "2025-11-18 12:34:56 UTC",  // Current UTC time will be shown if empty

    // Configuration of "Visit ... for more information"
    "more_information": {
        "hidden": false,
        "text": "cloudflare.com", 
        "link": "https://www.cloudflare.com/",
        "for": "more information",
    },

    // Configuration of the Browser/Cloudflare/Host status block
    "browser_status": {
        "status": "ok", // "ok" or "error"
        "location": "You",
        "name": "Browser",
        "status_text": "Working",
        "status_text_color": "#9bca3e",
    },
    "cloudflare_status": {
        "status": "error",
        "location": "Cloud",
        "name": "Cloudflare",
        "status_text": "Error",
        "status_text_color": "#bd2426",
    },
    "host_status": {
        "status": "ok",
        "location": "Website",
        "name": "Host",
        "status_text": "Working",
        "status_text_color": "#9bca3e",
    },
    // Position of the error indicator, valid options are 'browser', 'cloudflare', and 'host'
    "error_source": "host",

    "what_happened": "<p>There is an internal server error on Cloudflare's network.</p>",
    "what_can_i_do": "<p>Please try again in a few minutes.</p>",

    "ray_id": '0123456789abcdef',  // Random hex string will be shown if empty
    "client_ip": '1.1.1.1',

    // Configuration of 'Performance & security by ...' in the footer
    "perf_sec_by": {
        "text": "Cloudflare",
        "link": "https://www.cloudflare.com/",
    },
}