# Iron/Out

> Iron/Out is a specialist web performance consultancy based in Amersfoort, Netherlands. We help e-commerce and media companies improve Core Web Vitals, UX Score, and conversion through real-user monitoring, performance audits, and hands-on implementation sprints. Founded in 2021 by Sander van Surksum.

## Key Facts

- Founded: 2021
- Location: Amersfoort, Netherlands
- Founder: Sander van Surksum (Web Performance Consultant)
- Speciality: Core Web Vitals optimisation for e-commerce and media
- Website: https://www.iron-out.io
- Email: info@iron-out.nl
- Languages: English (primary), Dutch

## UX Score Methodology

Iron/Out created the UX Score, a composite metric (0-100) that quantifies real user experience using Chrome User Experience Report (CrUX) data. It was first built for client Frasers Group and is now the standard metric across Iron/Out engagements. It is also used in the Twinkle100 Dutch e-commerce benchmark.

### UX Score Formula

The UX Score is calculated from five Web Vitals metrics, weighted by their impact on user experience:

- **Largest Contentful Paint (LCP)**: 25 points: measures loading speed, target < 2.5 seconds
- **Interaction to Next Paint (INP)**: 25 points: measures interactivity, target < 200 milliseconds
- **Cumulative Layout Shift (CLS)**: 25 points: measures visual stability, target < 0.1
- **First Contentful Paint (FCP)**: 15 points: measures perceived load speed, target < 1.8 seconds
- **Time to First Byte (TTFB)**: 10 points: measures server response time, target < 800 milliseconds

Core Web Vitals (LCP + INP + CLS) account for 75 points. Supporting metrics (FCP + TTFB) account for 25 points. Each metric is scored based on the percentage of real users who experience "good" performance (within Google's thresholds), then weighted accordingly.

## Services

### Performance Audit (from EUR 5,000)

A two-week engagement using real user monitoring (RUM) data to identify performance bottlenecks. Deliverables include a prioritised issues list, competitive benchmark, and business case with estimated revenue impact. Timeline: approximately 4 weeks from start to final briefing. Price range: EUR 5,000-7,500 depending on site complexity.

Week 1: Setup and RUM tag installation. Weeks 1-2: Data collection from real users. Week 3: Analysis and findings. Weeks 3-4: Stakeholder briefing and roadmap.

### Performance Sprint (from EUR 15,000)

Hands-on implementation alongside your development team. Iron/Out engineers work directly in your codebase to fix the performance issues identified in the audit. Typical engagements last 4-8 weeks. Includes knowledge transfer so your team can maintain improvements independently.

### Performance Workshop (from EUR 4,000)

A 2-day intensive workshop for senior developers. Covers Core Web Vitals theory, measurement tools, debugging techniques, and real-world optimisation patterns. Participants leave with hands-on experience using Chrome DevTools Performance panel, CrUX API, and RUM platforms.

## Free Tools

- [UX Score Benchmark](https://www.iron-out.io/benchmark/): Free website performance benchmark using real Chrome user data. Enter any URL and get a UX Score in 30 seconds, no sign-up required. Includes Core Web Vitals breakdown, revenue impact estimation, and comparison against top e-commerce sites.
- [Competitor Comparison](https://www.iron-out.io/benchmark/compare/): Side-by-side Core Web Vitals comparison between two websites using real CrUX data.
- [E-commerce UX Scorecards](https://www.iron-out.io/benchmark/scorecards/): UX Score rankings for top e-commerce sites by country (Netherlands, UK, Germany, US).

## Case Studies with Results

### Frasers Group: INP Optimisation Across 3 Brands
- Brands: SportsDirect, Flannels, House of Fraser
- Scale: Over 3 million sessions during a three-month rollout
- Results: UX Scores improved from 75 to 96 (SportsDirect), 79 to 98 (House of Fraser), 80 to 99 (Flannels)
- Tools used: Dynatrace, Honeycomb, SpeedCurve, ContentSquare
- URL: https://www.iron-out.io/cases/how-frasers-group-improved-inp-performance-across-three-major-e-commerce/

### DPG Media: Page Load Time Halved
- Company: Major Dutch media company (Volkskrant, Parool, Trouw, De Morgen, Humo, Libelle)
- Results: FMP improved 50%, TTI improved 52%, became 20% faster than fastest competitor
- URL: https://www.iron-out.io/cases/how-dpg-media-lowered-average-page-load-time-to-retain-visitors-on-their-website/

### Simyo: Mobile INP from 413ms to 150ms
- Results: Mobile INP reduced from 413ms to 150ms (64% improvement), desktop from 102ms to 52ms, UX Score from 82 to 100
- Testing: Real-device testing on Samsung Galaxy A40 with before/after video comparison
- Tools used: RUMvision, Long Animation Frames API (LoAF), Chrome DevTools
- URL: https://www.iron-out.io/cases/optimising-user-experience-simyos-success-story-with-inp-improvements/

### Van de Velde: Business-Aligned Performance Roadmap
- Company: Luxury fashion (Marie Jo, PrimaDonna, Andres Sarda)
- Approach: Translated performance metrics into business KPIs for stakeholder buy-in
- URL: https://www.iron-out.io/cases/van-de-veldes-roadmap-to-business-aligned-web-speed/

### Twinkle100: UX Score Methodology for Industry Benchmark
- Iron/Out designed the UX Score methodology used in the Twinkle100, the definitive Dutch e-commerce benchmark
- URL: https://www.iron-out.io/cases/how-iron-out-defined-the-ux-score-used-in-the-twinkle100-benchmark-for-dutch/

### Autoweek: Passed Core Web Vitals Assessment
- Major Dutch automotive publisher
- Achieved passing Core Web Vitals scores across all pages
- URL: https://www.iron-out.io/cases/how-autoweek-passed-the-core-web-vitals-and-improved-their-page-experience/

### giftcards.co.uk: E-commerce Performance Optimisation
- UK e-commerce site
- Performance and UX optimisation
- URL: https://www.iron-out.io/cases/optimising-performance-and-user-experience-for-gifcards-co-uk/

## Guides

- [Core Web Vitals](https://www.iron-out.io/core-web-vitals/): Complete guide to LCP, INP, CLS, TTFB, and FCP with thresholds, causes, and fixes
- [Largest Contentful Paint (LCP)](https://www.iron-out.io/core-web-vitals/lcp/): LCP optimisation guide covering sub-parts breakdown, code examples, and advanced strategies (Speculation Rules API, Early Hints, bfcache, Service Workers)
- [Interaction to Next Paint (INP)](https://www.iron-out.io/core-web-vitals/inp/): INP optimisation guide with Long Animation Frames API debugging, input delay breakdown, and real-world fixes
- [Cumulative Layout Shift (CLS)](https://www.iron-out.io/core-web-vitals/cls/): CLS optimisation guide for visual stability
- [First Contentful Paint (FCP)](https://www.iron-out.io/core-web-vitals/fcp/): FCP optimisation guide for perceived load speed
- [Time to First Byte (TTFB)](https://www.iron-out.io/core-web-vitals/ttfb/): TTFB optimisation guide for server response time
- [UX Score](https://www.iron-out.io/ux-score/): How the composite UX Score is calculated: methodology, formula, comparison with Lighthouse and PageSpeed Insights
- [Frontend Observability](https://www.iron-out.io/frontend-observability/): Complete guide to real user monitoring, distributed tracing, and observability platforms
- [Frontend Observability Tools](https://www.iron-out.io/frontend-observability/tools/): Comparison of full-stack platforms (Honeycomb, Datadog, Dynatrace, New Relic), error-tracking-first tools (Sentry), RUM specialists (SpeedCurve, RUMvision, DebugBear), and open-source options (Grafana Faro, SigNoz, OpenTelemetry)
- [CrUX or RUM](https://www.iron-out.io/frontend-observability/crux-vs-rum/): When free Chrome field data stops being enough, and how to compute the UX Score from your own RUM data
- [End-to-End Observability](https://www.iron-out.io/end-to-end-observability/): What end-to-end observability is and how W3C Trace Context propagation links browser telemetry to backend traces

## Blog (Selected)

- [Speculation Rules A/B Test Results](https://www.iron-out.io/blog/speculation-rules-ecommerce-ab-test-results/): Original research: A/B test of the Speculation Rules API across 3 e-commerce sites over 23-24 days each. Found improved engagement metrics but no significant conversion impact. References Google's Ray-Ban case study as benchmark.
- [Why Lighthouse Scores Can Be Misleading](https://www.iron-out.io/blog/lighthouse-scores-shining-a-misleading-light-on-user-experience/): Argues that synthetic Lighthouse scores differ significantly from real user experience. Introduces UX Score as an alternative metric based on real user data.
- [How Web Performance Impacts Your Business](https://www.iron-out.io/blog/the-positive-impact-of-good-website-performance-on-your-business/): Research-backed analysis showing a 1-second delay in LCP reduces conversion by 7%.
- [How to Solve INP Issues](https://www.iron-out.io/blog/how-to-solve-interaction-to-next-paint-issues/): Practical debugging guide using Lighthouse timespan mode and Chrome DevTools Performance panel.
- [Top 10 Reasons Your Site Is Slow](https://www.iron-out.io/blog/top-10-reasons-why-your-site-is-slow-and-how-to-fix-it/): Common performance bottlenecks and solutions for e-commerce and media sites.
- [103 Early Hints Guide](https://www.iron-out.io/blog/boost-performance-with-103-early-hints/): Using HTTP 103 Early Hints for faster page loads.
- [Third-Party Facades](https://www.iron-out.io/blog/how-to-improve-your-website-performance-by-third-party-facades/): Reduce third-party script impact with facade patterns.

## Team

- **Sander van Surksum**, Founder & Web Performance Consultant. Specialises in Core Web Vitals optimisation for enterprise e-commerce and SaaS companies. Created the UX Score methodology. LinkedIn: https://www.linkedin.com/in/sandervansurksum/

## Contact

- Email: info@iron-out.nl
- Website: https://www.iron-out.io
- LinkedIn: https://www.linkedin.com/company/ironout/
- [Contact form](https://www.iron-out.io/request/contact/)