npe4j.com

.com crawl

First seen 2026-04-12 · Last seen 2026-05-08 · ok HTTP/1.1 200 6220 ms crawled 2026-05-08

US · 188.114.96.3 · AS13335 Cloudflare, Inc.

Reputation 87/100 weak security headers no dmarc policy

Classifying

HTML metadata

Title: npe4j（NullPointerException for Java）
Language: zh-CN

Technology

CDN: Cloudflare
CMS: Gatsby

Analytics

Google Tag Manager

Third-party hosts loaded (4)

avatars.githubusercontent.com×30
panjiachen.github.io×20
cdnjs.cloudflare.com×1
www.googletagmanager.com×1

Registration

Registrar

Alibaba Cloud Computing (Beijing) Co., Ltd.

Created

2019-07-29

Expires

2026-07-29 71 days left

Updated

2025-07-25

Name servers

carlos.ns.cloudflare.com
ingrid.ns.cloudflare.com

DNS records live

NS

carlos.ns.cloudflare.com
ingrid.ns.cloudflare.com

MX

10 mx.zoho.com
20 mx2.zoho.com
50 mx3.zoho.com

TXT

google-site-verification=jF8T8lkHgYsn1FaP7_RvWMn_q4-nplneLAk7MHTz27g

Email authentication weak

SPF: v=spf1 include:zohomail.com -all
strict (-all)
DMARC: not published
DKIM: no key found at common selectors

Certificate (current)

WE1

from 2026-03-30 to 2026-06-28

Expires in 41 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 30/100 Checked live page: https://npe4j.com/

findings

missing HSTS
missing Content Security Policy
missing frame protection
missing content type protection
missing Referrer Policy
missing Permissions Policy

Links to (7)

Linked from (1)

getaitools.app×2