website performance optimization

Website Performance Optimization

Sub-2.5s LCP, green Core Web Vitals, and the revenue that comes with them

A slow site kills conversions before you can measure the loss. Every 100ms of load time costs 1-2% of conversion rate. We audit, optimize, and monitor your site's performance until every visitor gets a fast experience - on the worst device on the worst network.

Deliverables
4 core deliverables
Timeline
4-6 weeks to major wins, ongoing monitoring
Pricing
Engagements from $6,500 · monitoring from $1,000/mo
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What's included

  • Full Core Web Vitals audit (LCP, INP, CLS, TTFB)
  • Image pipeline (AVIF/WebP, responsive, lazy) rebuild
  • Font optimization (subset, preload, swap strategy)
  • Third-party script audit + tag budget
  • CDN/edge configuration (Cloudflare, Vercel, custom)
  • Real-user monitoring (RUM) setup

What ships

  • Prioritized performance fix list
  • Implemented optimizations across images, fonts, scripts, CDN
  • Real-user monitoring live
  • Before/after report with conversion impact

What you walk away with

  • Sub-2.5s LCP on real devices, not just lab tests
  • Green Core Web Vitals sitewide
  • Measurable conversion lift attributable to speed

Performance engagements we ship typically cut LCP in half and lift conversion 8-20%. On any site doing meaningful revenue, the work pays for itself in weeks.

Speed is a revenue channel

Every performance study since 2010 confirms the same math: faster sites convert more. Amazon, Walmart, Pinterest, and countless smaller studies all agree - a 100ms improvement in load time reliably lifts conversion 1-2%. On a site doing $5M/year, that's $50K-$100K per 100ms.

Performance work has one of the cleanest ROI stories in digital. It's engineering-heavy, unglamorous, and almost always underinvested - which is why we can usually deliver dramatic wins even on sites that consider themselves "already optimized."

The 80/20 of Core Web Vitals

Almost all site-wide LCP failures come from three places: a huge hero image that isn't AVIF/WebP and responsive, a render-blocking font stack, or a third-party script that hijacks the main thread. Fixing those three is usually a 50-70% LCP improvement.

INP (the successor to FID) is the newer challenge - long tasks in JavaScript that make the site feel unresponsive. We profile with the Performance panel, identify the specific tasks, and either break them up or defer them off the critical path.

Real-user monitoring is the only truth

Lab tests miss the reality of a $150 Android on a rural 4G network. We install real-user monitoring (RUM) using Chrome UX Report, SpeedCurve, or a custom lightweight beacon so you see the 75th percentile of actual visitors - not the p50 of your MacBook Pro on wired ethernet.

That's the number Google ranks on, and it's the number that drives your conversion rate. Every optimization we ship is validated against RUM data before we call it done.

See if we're a fit

Get a personalized Website Performance Optimization plan

Answer 6 quick questions. If we're a fit, we'll show you exactly how website performance optimization would run inside your business and book your Growth Audit.

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See real website performance optimization results

Every engagement is measured. Browse our case studies for real outcomes from businesses that installed website performance optimization with us.

View case studies

Frequently asked

Isn't PageSpeed Insights enough?
It's a lab test on one device. We measure real-user metrics across your actual traffic - that's what Google ranks on and what your conversion rate reflects.
Do you handle mobile specifically?
That's most of the work. Mobile-first, with attention to worst-quintile network and device - because that's where conversion rate suffers most.
Can you work with our engineering team?
Yes - we deliver JIRA-ready tickets with clear acceptance criteria and can implement or advise depending on your team's bandwidth.

Pair with

Growth Strategy
The plan that makes every other dollar work harder
Websites & Sales Funnels
Sites that convert traffic into booked calls - not bounces
Paid Advertising
Profitable traffic on Meta, Google, TikTok, and YouTube
CRM & Workflow Automation
Every lead followed up. Every deal moved. Every time.
AI Chat & Voice Agents
A senior closer answering every lead, day or night
SEO & AEO
Show up when buyers ask Google - and when they ask ChatGPT
See all services →
Written and reviewed by
Chris Sanford, Founder & Chief Growth Strategist

Chris builds and leads the website performance optimization engagements at Irrefutable Momentum. Read more →

Ready to install website performance optimization?

Book a 30-minute Growth Audit. If we're a fit we'll show you exactly how the system would run inside your business.

Book a Growth Audit