If you’ve ever wondered what a web design agency actually does all day (beyond making things look nice), this guide is for you.

We’ll walk through the full process—from the first chat and strategy work to UX, design, development, SEO, accessibility, launch, and ongoing growth. We’ll also cover how to choose the right agency, what it typically costs in the UK, and common mistakes to avoid.

TL;DR:
A good web agency is part strategist, part designer, part developer, and part growth partner. You’re buying results—clarity, conversions, and a site that’s fast, accessible, and easy to manage—not just “pages on the internet.”

Why Businesses Hire a Web Design Agency/Company

Clarity & positioning → Turn your offer into a clear story that’s easy to understand.
User experience (UX) → Make it simple for website visitors to find what they need and take action.
Design & brand → Create a look and feel that builds trust and brand identity.
Development → Build a site that’s fast, secure, and easy to update.
Traffic & conversions → Bring the right people in (organic SEO within search engines) and turn visits into leads or sales (CRO).
Compliance & quality → Accessibility, security, GDPR, cookie consent, and robust testing for usability.
Ongoing website support → Continuous improvements once the site is live.

👉 If you’re looking for a web design agency in Cardiff, we share our approach below, along with examples from our recent work (like the AJL Mortgages project).

The End-to-End Process (What Actually Happens)

1) Discovery & Digital Strategy

Workshops & interviews → Goals, audience, competitors, industry, brand, success metrics.
Analytics & audit → What’s working today, where users drop off, tech issues.
Content & SEO gap analysis → What to say, which pages you need, and which keywords are worth targeting as part of a practical digital marketing strategy.
Output → A clear plan—site architecture, priorities, and roadmap.

2) UX Design & Information Architecture

User journeys → The main paths people take (homepage → service → enquiry, etc.).
Sitemap → Pages you need and how they connect.
Wireframes → Low-fidelity layouts showing content hierarchy.
📖 Resource: Nielsen Norman Group

3) UI & Creative Design

Design system → Colours, typography, spacing, buttons, forms, reusable components.
High-fidelity mockups → Homepage, service templates, case studies, blogs.
Interaction states → Hover effects, error states, mobile nav.
Accessibility baked-in → Contrast ratios, focus states, and readable type from day one.
📖 See WCAG essentials

4) Content Design & Messaging

Positioning & headlines → What do you do, for whom, and why it’s valuable.
Service pages that sell → Pain → Solution → Proof → Next step. For examples, see Website Design and Shopify Web Design.
Case studies → Problem, process, results, with real numbers if possible—like AJL Mortgages or Cobra Workwear.
On-page SEO → Titles, meta descriptions, heading structure, internal linking.
- If you’re moving platform, plan your redirects → see our Shopify SEO Migration Guide.

5) Web Development (The Build)

CMS → WordPress, Shopify, Sanity/Next.js (headless), WooCommerce.
Component library → Editors can build new pages without breaking design.
Performance → Image optimisation, lazy loading, caching, minification → aim to pass Core Web Vitals.
📖 Learn more: web.dev/vitals
📖 Practical tips: How to Boost Website Speed
Security & privacy → Updates, backups, HTTPS, cookie consent, GDPR basics.

6) QA, Testing & Accessibility Checks

Cross-browser & device testing.
Forms, search, redirects, and 404s.
Accessibility → Keyboard navigation, labels, alt text, landmarks.
Content checks → Broken links, typos, spacing.

7) Launch & Handover

Hosting & DNS changes.
301 redirects so old URLs keep SEO value (again, see Shopify SEO Migration Guide).
Analytics setup → GA4, conversions, Search Console verification, sitemap submission.
Editor training → Add pages, publish blogs, keep content tidy.
📖 Shopify merchants: Online Store 2.0 Guide

8) Growth & Continuous Improvement

SEO & content → Regular blogs/landing pages for topical authority (like this one). If you’re weighing platforms, read Shopify vs Other Platforms.
CRO → A/B testing, navigation tweaks, clearer CTAs, social proof.
Performance upkeep → As content grows, keep speed up. For ecommerce, see Top Shopify Speed Apps.
Feature roadmap → New templates, integrations, automations → part of broader digital transformation.

Services a Web Design Agency Typically Offers

Website strategy & consulting (and wider digital strategy)
UX design, wireframing, prototyping
Branding or brand refresh (with branding services)
UI design & design systems
Web development (CMS or headless)
SEO foundations & technical SEO for search engines
Copywriting & content design
Ecommerce builds (Shopify, WooCommerce)
Analytics, tracking & dashboards
Accessibility audits & remediation
Ongoing website support on retainers

Agency vs Freelancer: Which Is Right for You?

Freelancer (pros):

Lower cost for small projects
Direct communication with the doer
Flexible schedules

Freelancer (cons):

Limited capacity (holidays, illness, overlap)
Narrower skill set (design or dev, not both)
May need to coordinate multiple freelancers

Agency (pros):

Web design team of specialists (strategy, UX, design, dev, SEO, content)
Process & reliability (PM, QA, documentation)
Continuity (someone’s always available)
Speed when multiple specialists work in parallel

Agency (cons):

Higher price point
More structure (usually a benefit)

📖 If you’re choosing locally: Choosing a Web Design Agency in Cardiff.

How to Choose the Right Web Design Agency (Checklist)

✅ Look for:

Relevant case studies with clear outcomes → Our work
Process transparency (how they get you from A → B)
A sensible CMS you can update without code → e.g. Shopify Web Design
Performance & accessibility in live work (try a Lighthouse test)
Clear scope, timeline, proposal
Chemistry & communication

❓ Questions to ask:

How will you measure success beyond “the site is live”?
Who’s on the project team and how do we communicate?
What content is needed from us? Templates/examples?
What happens after launch? Do you offer retainers?
Can we see a demo of the editor experience?

What Does a Web Design Agency Cost in the UK?

Ballpark ranges (SMEs typically see):

Small brochure site (5–10 pages): £2k–£8k
SME marketing site (10–30 pages, custom design, CMS, integrations): £8k–£25k
Ecommerce (Shopify, WooCommerce, custom ecommerce design, integrations): £10k–£80k+
Large/enterprise/headless builds: £50k–£200k+

Engagement models:

Fixed-price project → Defined scope/timeline.
Retainer → Ongoing SEO, CRO, dev → £1k–£5k+/month.
Day rates → £350–£900/day depending on seniority.

📖 Ecommerce-specific: How Much Does a Shopify Store Cost (UK)?

Timelines (What to Expect)

Discovery & strategy → 1–3 weeks
UX & design → 2–6 weeks
Development → 3–8+ weeks
QA, content load & launch → 1–3 weeks

➡️ Small site → 6–8 weeks
➡️ Bigger builds → 12–16+ weeks

Common Mistakes to Avoid

❌ Starting with design before strategy
❌ Underestimating content (delays later)
❌ Ignoring performance → How to Boost Website Speed
❌ Skipping accessibility
❌ No post-launch plan → (SEO content & CRO are essential)
❌ Choosing the wrong CMS → For ecommerce, Shopify is safe & scalable

What Success Looks Like

✅ Clear story: visitors get it in seconds
✅ Fewer bounces, more enquiries/sales
✅ Better search visibility for the right terms
✅ Faster publishing: team edits pages/blogs without devs
✅ Growth platform: new landing pages, features without re-platforming → Why Us

FAQs

Q: What exactly is included in a web design agency project?
Strategy, UX, UI design, development, QA, SEO foundations, analytics setup, and training.

Q: What’s the difference between web design and development?
Design = how it looks & works for humans. Development = how it’s engineered under the hood.

Q: Do I need a brand before I start?
Not always—many projects include a brand refresh.

Q: Will I be able to edit the site myself?
Yes—via CMS with reusable components.

Q: Can you help after launch?
Absolutely—through retainers for SEO content, CRO, performance, features.

Q: What about digital marketing?
On-page SEO is baked in. Post-launch → ongoing content, SEO, PPC, email, and other digital marketing solutions.

Deep-Dive Snippets (Extra Context)

Branding → If you need naming/identity, a branding agency can partner with your web team.
Digital marketing → Your site underpins campaigns (content, email, PPC, social, PR).
Ecommerce → We deliver Shopify & WooCommerce builds with conversion-friendly templates.
Responsive web design → Every site adapts smoothly across devices.
Search engines → We build with SEO architecture & crawlability in mind.
Web development vs website design → Website design is often asked for, but a strong web design company should do both design and dev.
Innovation → Reusable components, smarter navigation, faster load.
Rebrand → Align timelines if you’re mid-rebrand.
Marketing → Campaign pages, lead magnets, analytics, automation hooks.
Shopify → See Shopify Web Design, Shopify Development, Shopify Agency. If switching, see Shopify SEO Migration Guide.

Ready to Chat?

If you’re exploring a web design agency in Cardiff (we also work with clients in London and Surrey), we’d love to hear about your goals and share ideas for quick wins and long-term growth.

👉 Start a project | Contact us

What Does a Web Design Agency Do?