The 12-point checklist
(1) SSL active — full https:// only, no mixed content warnings. (2) Mobile tested on 3 real devices — emulators miss touch issues. (3) LCP under 2.5s on a throttled 3G connection (DevTools Performance tab). (4) Form submissions tested end-to-end — submission lands in CRM, triggers welcome email, populates expected fields. (5) Analytics firing — verify pageview, conversion event, and any custom events all show in real-time view. (6) Structured data validates against Google's Rich Results Test. (7) OG image renders on Twitter, LinkedIn, Slack, iMessage, WhatsApp — each renders at slightly different aspect ratio. (8) Hero CTA visible above the fold on 375px width — the iPhone SE width — without any scrolling. (9) No broken external links — run a link checker, fix or remove dead links. (10) Robots.txt allows GPTBot, ClaudeBot, PerplexityBot, Googlebot, Bingbot — confirm none disallowed. (11) 5-second test with 3 people outside your team — they can articulate what the product does. (12) Form failure fallback — if the form fails, the user sees a clear retry path, not a generic error.
The bug profile we see most
Across 1,000+ pages we've analyzed, the most common bugs are mundane: form submission silently fails on certain mobile browsers, OG image is the default Vercel placeholder, structured data has a typo and emits no signals, mobile hero CTA is below the fold on iPhone SE, third-party script blocks paint and tanks LCP. None of these are "hard" bugs — they're skipped checks. The 12-point list catches them in 30 minutes.
Post-launch: the first 72 hours
After launch, monitor conversion rate and bounce rate by source. If bounce rate exceeds 70% on any source, the message-match between source and page is broken. If conversion is below 50% of expected on day 3, run our page analysis to surface what the pre-launch checklist missed.