HeaderCheck

Name: HeaderCheck
Rating: 5 (6 reviews)
Author: YvonLabs

Local security header audit. Runs offline. Made by YvonLabs.

As of June 2026, HeaderCheck has 30 users and a 5.00/5 rating from 6 reviews in the Developer Tools category.

YvonLabs Developer Tools

Chrome Web Store ↗.crx

Users+7.1%

Rating0%

5.00

6 reviews

Reviews0%

Version

0.3.0

Manifest V3

History

7 snapshots

Tracking since Apr 1, 2026.

View as table

Date	Users	Rating	Reviews	Version
Apr 1, 2026	28	5.00	6	0.3.0
Apr 18, 2026	29	5.00	6	0.3.0
Apr 28, 2026	37	5.00	6	0.3.0
May 8, 2026	28	5.00	6	0.3.0
May 15, 2026	31	5.00	6	0.3.0
May 24, 2026	30	5.00	6	0.3.0
Jun 3, 2026	42	5.00	6	0.3.0
Now	30	5.00	6	0.3.0

Permissions & access

Permissions: activeTabstoragewebRequest
Host access: <all_urls>

Screenshots

About

HeaderCheck is a lightweight, privacy-respecting Chrome extension that analyzes HTTP response headers for the active tab and evaluates a site's security and privacy posture.

It uses a deterministic weighted scoring model (SCM-2025.1) to calculate a 0–100 score based on the presence and validity of key security headers, including CSP, HSTS, COOP, COEP, CORP, Referrer-Policy, Permissions-Policy, X-Frame-Options, and X-Content-Type-Options.

     • Instant analysis  
     • No remote calls or telemetry  
     • Graded vs informational headers for clarity  
     • Clean, minimal interface  
     • Focused on modern browser security and privacy best practices  
     • EU-aligned philosophy emphasizing transport integrity and referrer minimization

HeaderCheck runs entirely on-device inside Chrome’s extension sandbox. No data leaves your browser, ever.