fftw.org website report
FFTW Home Page
Last scanned · 1 view
Overall score
Fair
About fftw.org
fftw.org is a website. It describes itself as “A fast, free C FFT library; includes real-complex, multidimensional, and parallel transforms”.
Score profile
Top issues to fix
14 issues found · 4 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.
No H1 heading found
SEOAdd exactly one H1 describing the page's main topic — it anchors the document outline for search engines and screen readers.
Missing viewport meta tag
AccessibilityAdd <meta name="viewport" content="width=device-width, initial-scale=1"> — without it the site is broken on mobile.
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.
+8 more issues — details in the sections below.
How it compares
fftw.org scores higher overall than 14% of the 163,243 sites we have scanned.
vs. All scanned sites
163,243 sitesThe dot is this site; the tick is the typical (median) score for the group. The number on the right is the percentile: the share of the group this site scores above.
Technology stack
fftw.org is built with Nginx.
Servers (1)
Hosting & DNS
- IP address
- —
- ASN
- —
- IPv6
- Not supported
- HTTP
- HTTP/1.1
Show DNS record values
TXT record contents are not republished; only their count is shown.
Security
fftw.org uses TLS 1.3 with a certificate valid for 83 more days and sets 0 of 6 recommended security headers.
Security headers0 of 6 set
- HSTSForces HTTPS
- CSPBlocks injected scripts
- X-Frame-OptionsStops clickjacking
- X-Content-TypeStops MIME sniffing
- Referrer-PolicyLimits URL leakage
- Permissions-PolicyRestricts browser features
TLS certificate
- Names covered
- 5
- Cookies set
- 0
Email security
fftw.org scores B for email security, with SPF and DMARC policy “reject”.
- SPFGood
Rejects senders not listed (-all).
- DMARCGood
Forged mail is rejected; reports are collected.
- MTA-STSNot set
Not published; mail to this domain can be downgraded to plaintext.
- BIMINot set
Not published (optional).
Performance & carbon
fftw.org scores 100/100 for performance, with an estimated load time of 0.2 s. A visit emits an estimated 0.00 g of CO2 (grade A+).
Page weight
- HTML 13.3 KB
- Est. load
- 241 ms
- Response
- 241 ms
- Scripts / CSS
- 0 / 1
Carbon per visitA+
0.00 g CO2 per uncached view
Estimate from the Sustainable Web Design model. HTML, JavaScript and CSS only; images, video and fonts are not measured. Treat it as a lower bound for comparing pages, not an audit.
SEO & accessibility
fftw.org scores 60/100 for SEO and 60/100 for accessibility, with 6 SEO issues to fix.
Heading structure
No H1 found.
Image alt text
3 images · 1 without alt text · 0 lazy-loaded
Links
- Internal 31
- External 22
- Broken 2
SEO issues6
- Missing canonical link
- No H1 heading found
- No structured data (JSON-LD) found
- Missing OpenGraph tags
- robots.txt not found
- sitemap.xml not found
Accessibility issues4
- More than 20% of images are missing alt text
- No H1 heading found
- Missing <html lang> attribute
- Missing viewport meta tag
Technical details
Page metadata, social tags, crawl files and scan information.
Meta tags
- Title
- FFTW Home Page
- Description
- A fast, free C FFT library; includes real-complex, multidimensional, and parallel transforms. Benchmarked against many other FFTs.
- Canonical
- Language
- Robots meta
Crawl files
- robots.txt
- Not found
- Disallow rules
- 0
- sitemap.xml
- Not found
- URLs in sitemap
- 0
Structured data
No JSON-LD types declared.
- Microdata items
- 0
- RDFa items
- 0
Scan
- Final URL
- https://fftw.org
- HTTP status
- 200
- Redirects
- https://fftw.org
- Scanned
- Aug 24, 2026, 1:22 PM
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<a href="https://sitegraph.tech/site/fftw-org"><img src="https://sitegraph.tech/badge/fftw-org.svg" alt="fftw.org on SiteGraph" width="190" height="20" /></a>See something wrong on this report? Request a correction or ask for something to be removed.
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Frequently asked questions about fftw.org
- What is fftw.org?
- fftw.org is a website. It describes itself as “A fast, free C FFT library; includes real-complex, multidimensional, and parallel transforms”.
- What technology does fftw.org use?
- fftw.org is built with Nginx.
- Is fftw.org secure?
- fftw.org uses TLS 1.3 with a certificate valid for 83 more days and sets 0 of 6 recommended security headers.
- Is fftw.org protected against email spoofing?
- fftw.org scores B for email security, with SPF and DMARC policy “reject”.
- How does fftw.org compare with similar sites?
- fftw.org scores higher overall than 14% of the 163,243 sites we have scanned.
- What is fftw.org's overall score?
- fftw.org has an overall SiteGraph score of 71/100, combining SEO (60), performance (100), security (65) and accessibility (60).
Open Graph & Twitter