What powers pbsbooks.org?
Last seen Jun 2026 · 37 technologies across 21 categories
Analytics
Google Analytics
since Sep 2020
Microsoft Clarity
since May 2024
Caching
Varnish
since Dec 2025
CDN
Cloudflare
since Aug 2023
Fastly
since Dec 2025
CMS
Databases
Font scripts
Twitter Emoji (Twemoji)
since Sep 2020
Typekit
since Feb 2021
JavaScript frameworks
JavaScript libraries
Marketing automation
OptinMonster
since Aug 2023
Miscellaneous
Open Graph
since Aug 2023
RSS
since Aug 2023
PaaS
Pantheon
since Dec 2025
Performance
Priority Hints
since Feb 2024
Programming languages
PHP
since Sep 2020
RUM
New Relic
since Dec 2025
Security
HSTS
since Mar 2024
Tag managers
Google Tag Manager
since Sep 2020
UI frameworks
Video players
Web servers
Nginx
since Aug 2023
Webmail
Microsoft 365
since Feb 2025
WordPress plugins
The Events Calendar
since Aug 2023
Audience
- 54% desktop
- 46% phone
United States
Countries where the site has Chrome traffic, strongest markets first.
Open Page Rank
4.73 / 10 · ranked #290,388 of all domains
117 referring domains · OpenPageRank
Core Web Vitals
| LCP | 2.2 s |
| INP | 75 ms |
| CLS | 0.05 |
| TTFB | 500 ms |
Real user p75, Chrome UX Report, Jun 2026.
Page
- Language: English (United States)
- CDN: Fastly
- Weight: 12.4 MB · 191 requests
- WordPress theme: avada · all themes
- Structured data: JSON-LD, OpenGraph, Twitter Cards
Homepage as crawled by the HTTP Archive, Jul 2026.
Full technology history →
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Recent changes
- dropped Google Font API Jun 2026
- dropped React Jun 2026
- dropped styled-components Jun 2026
- detected Google Font API Apr 2026
- detected React Apr 2026
- detected styled-components Apr 2026
- detected OptinMonster Jan 2026
- detected OptinMonster plugin Jan 2026
- dropped WP Rocket Jan 2026
- detected Fastly Dec 2025
- detected MariaDB Dec 2025
- detected New Relic Dec 2025
- detected Pantheon Dec 2025
- detected Twitter Emoji (Twemoji) Dec 2025
- detected Varnish Dec 2025
- dropped OptinMonster Oct 2025
- dropped OptinMonster plugin Sep 2025
- dropped Google Font API Aug 2025
- dropped React Aug 2025
- dropped styled-components Aug 2025