Spreadsheetpreview

PDF.js for spreadsheets. Preview Excel XLSX files directly in the browser with no upload, no server, and no Microsoft Office dependency.

Productivity

Estimated origin: Netherlands

Added July 7, 2026 · Last analysed July 7, 2026 · via Hacker News · 57% unique tagline

Own this Launch?

StackScope is a free public catalogue of indie launches. We find launches on Product Hunt, Hacker News and similar feeds, then crawl each site to detect its tech stack and score it for launch readiness: DNS, security headers, SEO basics. This page is what we saw on 7 July 2026; the live site may have changed since.

Spreadsheetpreview is early-stage. Visible gaps: missing several security headers, incomplete legal pages, and no robots.txt or sitemap.

Launched on Hacker News on July 7, 2026. The site is hosted on Hetzner Online GmbH in Germany, with a domain registered 12 weeks before launch. We've detected 6 technologies on this site, covering analytics, developer tools, DNS providers, and business email. The stack includes Brevo, Caddy, and Fastmail.

If you own this site, refresh the snapshot and see the full fix list any time →

3.1

StackScope Score

Poor

52/100 Launch Readiness

Partially ready

1/6 Security Headers

Poor

2/3 Legal

Partial

0/2 Crawl files

Missing

92/100 Performance

Fast

Vibe Score 0 · No AI signals

How much the site looks AI-generated. Informational pattern-match signal, not a verdict. Does not feed the StackScope Score. See which fingerprints fired →

Tech Stack (6)

Infrastructure

DNS	mijn.host DNS
Server	Caddy

Business email	Fastmail (3)
Email marketing	Brevo

Build & Framework

Developer tools	SheetJS

Analytics & Marketing

Analytics	Umami (2)

Infrastructure

Network

HETZNER-CLOUD2-AS - Hetzner Online GmbH, DE

AS213230 · DE

DNS

mijn.host DNS

Authoritative nameserver

DNSSEC

Enabled

DNSKEY records published. DNS responses signed.

Green hosting

Not green hosted

No green-energy record. Data from The Green Web Foundation.

SSL Certificate

Let's Encrypt

Valid 7 Jul 2026 to 5 Oct 2026

Certificate as captured in this snapshot, not a live check.

Domain Age

2 months

Registered Apr 2026 · Hosting Concepts B.V. d/b/a Registrar.eu

Email Security

⚠

SPF ?all Neutral (?all). Monitoring only, no enforcement.

✓

DKIM Detected via known email provider

✗

DMARC p=none None (p=none). Monitoring only.

MTA-STS Not deployed. Mail to your domain can be downgraded to plaintext en route.

TLS-RPT Not configured. You won't hear about silent SMTP TLS handshake failures.

Storage (0)

This site uses no client-side storage we could detect on page load.

Readiness Breakdown How?

✓ Custom title and meta description

✓ Responsive viewport meta tag

✓ Semantic HTML (nav, main, article)

- Open Graph tags (title, image, description)

- Canonical URL declared

- Twitter card meta tags

- Favicon present

Performance How?

375 ms Server response

48% Faster than peers

592 ms Largest contentful paint

0.00 Cumulative layout shift

1.6 MB Page weight

1 KB Image weight

2 Third-party domains

0 Console errors

0 Failed requests

⚠ 1 images: 1 oversized, 1 without width/height, 1 missing alt text

Indicative grade from a single automated render, not a substitute for Lighthouse or field data, and not part of the StackScope score.

AI Stance

No AI stance declared

✗ llms.txt published

✓ No AI bots blocked in robots.txt

Content-Signal

? No directive declared

Link headers

? None advertised

Well-Known Files

✗ robots.txt

✗ sitemap.xml

✗ security.txt

✗ llms.txt

✗ ads.txt

✗ humans.txt

Legal

? Privacy Policy not detected

✓ Terms of Service

/license

? Analytics present, but it set no tracking cookies on our visit (it may be opt-in-gated).

Security Headers (1/6)

✗

Referrer-Policy

✗

X-Frame-Options

✗

Permissions-Policy experimental (check browser support)

✓

X-Content-Type-Options

✗

Content-Security-Policy

✗

Strict-Transport-Security

–

X-XSS-Protection deprecated (use Content-Security-Policy)

Build

3 JS files

1 CSS files

2 Third-party domains

Brand Colours

Something not look right? If a technology shown here is wrong or out of date, email [email protected] and we'll review it.