tc39.es
TC39 - Specifying JavaScript.
Last scanned Jul 27, 2026, 10:43 AM · 1 view
Overall score
Great
Summary
This website is hosted on Fastly. SEO is fair (70/100) and accessibility is excellent (100/100). Security scores fair (65/100) and performance excellent (100/100). Top issue: Missing meta description.
- United States
- Hosted on Fastly
Top issues to fix
9 issues found · 3 high priority
Missing Strict-Transport-Security header
SecurityAdd HSTS so browsers always use HTTPS — this closes the protocol-downgrade attack window.
Missing Content-Security-Policy header
SecurityAdd a CSP to control which sources can run scripts — the strongest single defense against XSS.
Missing meta description
SEOAdd a ~150-character meta description to control your search-result snippet and lift click-through rate.
Missing X-Content-Type-Options header
SecurityAdd X-Content-Type-Options: nosniff to stop MIME-sniffing attacks.
Missing X-Frame-Options header
SecurityAdd X-Frame-Options (or a CSP frame-ancestors rule) to prevent clickjacking via hidden iframes.
Missing canonical link
SEOAdd <link rel="canonical"> so search engines know which URL variant to index.
+3 more issues — details in the sections below.
SEO
5 issue(s) found
Performance
219 ms
Security
HTTPS & header checks
Accessibility
0 issue(s) found
Organization
Company details published in this site's own structured data.
Meta tags
- Title
- TC39 - Specifying JavaScript.
- Description
- Canonical
- Language
- en-US
- Charset
- UTF-8
- Viewport
- width=device-width,minimum-scale=1,initial-scale=1
- Robots meta
- Manifest
Technologies
Detected frameworks, languages, and tools.
No technologies detected.
Hosting & CDN
DNS records
| Type | Value |
|---|---|
| A |
|
| AAAA | — |
| MX |
|
| TXT |
|
| NS |
|
| CAA | — |
| CNAME | — |
| IPv6 support | No |
TLS / SSL certificate
- Version
- TLS 1.3
- Issuer
- Let's Encrypt
- Subject
- tc39.es
- Valid from
- Jun 28, 2026
- Valid to
- Sep 26, 2026
- Days until expiry
- 61
- SAN domains
- tc39.es
Security headers
- Strict-Transport-SecurityMissing
- Content-Security-PolicyMissing
- X-Frame-OptionsMissing
- X-Content-Type-OptionsMissing
- Referrer-PolicyMissing
- Permissions-PolicyMissing
Compression: gzip · 0 cookie(s) observed
Content & assets
Headings
H1 1 · H2 4 · H3 5
Links
27 internal · 43 external · 0 broken
Images
2 total · 0 missing alt
Scripts / Styles
1 scripts · 3 stylesheets
JS / CSS size
2.2 KB · 16.7 KB
Page size
35.0 KB
Robots.txt & Sitemap
- robots.txt
- Not found
- Disallow rules
- 0
- sitemap.xml
- Not found
- URLs in sitemap
- 0
SEO issues
- Missing meta description
- Missing canonical link
- Missing OpenGraph tags
- robots.txt not found
- sitemap.xml not found
Accessibility issues
No accessibility issues detected.
Scan details
- Requested URL
- https://tc39.es
- Final URL
- https://tc39.es
- HTTP status
- 200
- HTTP version
- HTTP/2
- Response time
- 219 ms
- HTML size
- 35.0 KB
- Redirect chain
- https://tc39.es
See something wrong on this report? Request a correction
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Frequently asked questions
- What technology does tc39.es use?
- We did not detect any specific technologies for tc39.es in the latest scan.
- Is tc39.es secure (HTTPS)?
- Yes. tc39.es uses TLS 1.3 with a certificate issued by Let's Encrypt, valid until Sep 26, 2026.
- Who hosts tc39.es?
- tc39.es is hosted on Fastly, behind Fastly CDN.
- What is tc39.es's SEO score?
- tc39.es scored 70/100 for SEO in the latest analysis (fair).
- What is tc39.es's overall website score?
- tc39.es has an overall SiteGraph score of 82/100, combining SEO, performance, security, and accessibility.
OpenGraph & Twitter Card
OpenGraph
Twitter Card