What powers 
ptb.de?
Last seen Sep 2026 · 50 technologies across 20 categories
Analytics
CDN
CMS
Font scripts
Issue trackers
JavaScript frameworks
JavaScript graphics
JavaScript libraries
LMS
Miscellaneous
Operating systems
Photo galleries
Programming languages
Rich text editors
Security
UI frameworks
Video players
Web frameworks
Web servers
Webmail
AI Crawlers
Blocks 1 of 33 AI crawlers we track by name in its robots.txt. Checked Sep 2026.
Training crawlers
- ClaudeBot Blocked
The other 32 AI crawlers we track are not mentioned and only inherit the catch-all rules that apply to every crawler.
- robots.txt found
- llms.txt not found
- ai.txt not found
- Sep 2026 claudebot added to robots.txt
- Sep 2026 claudebot removed from robots.txt
- Sep 2026 claudebot added to robots.txt
Top search keywords
| Keyword | Position | Est. monthly visits |
|---|---|---|
| easter when is easter | #12 | 3,800 |
| capacitance units | #2 | 1,100 |
| co-60 | #2 | 1,100 |
| farad si units | #3 | 430 |
| capacitance | #6 | 410 |
| utc universal time | #22 | 410 |
| 1 kg | #6 | 340 |
| co 60 | #2 | 320 |
| deutschland time | #25 | 280 |
| unit of measure for electrical resistance | #2 | 260 |
| is today easter sunday | #7 | 250 |
| time in germany | #22 | 220 |
| time in germany | #22 | 220 |
| what time is it in germany | #60 | 210 |
| what is coordinated universal time | #21 | 210 |
| germany summer time | #2 | 200 |
| easter weekend | #8 | 200 |
| cest time | #14 | 190 |
| avogadro constant | #33 | 170 |
| easter sunday 2007 | #2 | 160 |
| easter day 2007 | #2 | 160 |
| second | #22 | 130 |
| unit of resistance | #2 | 130 |
| unit of measurement for electrical resistance | #2 | 130 |
| easter 1980 | #1 | 120 |
The site's top keywords in Google (US), with the visits each one is estimated to bring per month.
Top backlinks
Top links pointing at the site, one per source domain, strongest first. The anchor text opens the page carrying the link.
AI Crawlers
1 of 33 AI crawlers blocked
Audience
- 72% phone
- 24% desktop
- 3% tablet
Germany
Austria
Switzerland
India
United States
Italy
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
7.72 / 10 · ranked #12,656 of all domains
1,580 referring domains · OpenPageRank
Search traffic
18,900 est. monthly organic visits (US)
1,978 keywords in Google's top 30
Core Web Vitals
| LCP | 1.6 s |
| INP | 50 ms |
| CLS | 0 |
| TTFB | 300 ms |
Real user p75, Chrome UX Report, Aug 2026.
Page
- Weight: 0.6 MB · 38 requests
Homepage as crawled by the HTTP Archive, Sep 2026.
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Closest technology stacks among the highest-authority sites we track; "shared" counts the distinctive technologies in common.
Organisation
- Physikalisch-Technische Bundesanstalt
- Founded: 1887
- Sector: research and experimental development on natural sciences and engineering, public sector, research and development
- Country: Germany
From Wikidata (CC0).
Infrastructure
- Hosted on DFN Verein zur Foerderung eines Deutschen Forschungsnetzes e.V. (192.53.103.121, IPv6)
- DNS: dfn.de
- Email: ptb.de
- Email security: no SPF record, no DMARC record, DNSSEC signed, CAA
- SSL: Let's Encrypt, RSA 4096, expires Dec 2026
- Common Crawl link graph: rank 13,430, 125 hosts
DNS records as swept Sep 2026, certificate as seen Sep 2026. How the web is hosted
Subdomains
| Host | Techs |
|---|---|
| conferences.ptb.de | 16 |
| gitlab1.ptb.de | 13 |
| www.eastern-partnership.ptb.de | 13 |
| www.wimer.ptb.de | 12 |
| www.dcc-conference-2023.ptb.de | 11 |
| www.dcc-conference-2024.ptb.de | 11 |
| www.qi-digitalforum2025.ptb.de | 11 |
| www.qi-learning.ptb.de | 11 |
| www.dcc-conference-2026.ptb.de | 10 |
| www.tdot.ptb.de | 9 |
| box.ptb.de | 8 |
| www.chemsafe.ptb.de | 8 |
| www.imeko-gh2fuels.ptb.de | 8 |
| www.ptb.de | 8 |
| www.dkd.ptb.de | 7 |
| www.ausbildung.ptb.de | 6 |
| www.zukunftstag.ptb.de | 5 |
| oar.ptb.de | 4 |
| uhr.ptb.de | 3 |
| ppp.ptb.de | 2 |
Full technology history →
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Recent changes
- dropped OpenSSL Jun 2026
- dropped Windows Server Jun 2026
- detected Plausible Apr 2026