How to Hire a Web Development Agency
What to ask, what to demand, what to avoid. A buyer's guide for founders, marketing leaders, and operators evaluating web development agencies for a marketing site, SaaS site, or web app project.
Hiring a web development agency is hard because the gap between the best and the worst is huge, and the worst look like the best in a sales meeting. This guide is what our team would tell a friend or peer who is about to brief 3 to 5 agencies and pick one. Written so you do not need to be technical to use it.
1. Get clear on what you are actually buying
Web development is not one thing. A marketing site, a SaaS marketing site with feature pages and pricing, an e-commerce store, a custom web app, and a multi-tenant platform are all 'web development' but require very different skills and have very different costs. Be specific in your brief about which one you are buying so agencies can quote accurately and you can compare like with like.
The Magnis AI Website Cost Calculator gives a rough budget range per type. Use it to set internal expectations before you start agency conversations, so you can tell quickly when a quote is way outside reasonable range either way.
2. The five questions that separate good agencies from bad
Ask these on the first call:
First: Can I see three live sites you have built in the last 18 months that are similar to what I need? (Watch for: live URLs not screenshots, recent work not 5-year-old portfolio pieces, in your industry or one structurally similar.)
Second: Who exactly will work on my project, and what is their seniority? (Watch for: real names not 'a team of experts', senior leads with 5+ years experience, not pure pyramid staffing.)
Third: What is your process for handling change requests during the build? (Watch for: a defined process, transparent quoting for scope changes, not 'we will figure it out as we go'.)
Fourth: How do you handle handover and post-launch support? (Watch for: documented handover, code in your repository under your account, optional post-launch support that is not a hostage situation.)
Fifth: Why should I pick you over the other four agencies I am talking to? (Watch for: specific differentiation grounded in capability or experience, not generic 'we care more', not pricing-only.)
3. Stack questions to ask
If you do not know the answers to these, ask the agency to explain them in plain language. Watch for whether they can:
What CMS or stack do you recommend and why? Is it the right fit for my team to maintain content after launch? (Watch for: stack chosen for your use case not the agency's preference. Headless Next.js + CMS is the default for marketing sites; WordPress is fine for content-heavy editorial; Shopify for e-commerce.)
How will the site perform on Core Web Vitals? Will it pass Lighthouse 90+ on mobile? (Watch for: a concrete commitment, ideally with their previous sites as proof.)
How is SEO handled during the build? Schema, sitemap, redirect map if migrating? (Watch for: SEO baked into build process, not bolted on after.)
How does the site stay accessible (WCAG AA)? (Watch for: accessibility tested during build, not assumed.)
Where will the site be hosted, and what does that cost ongoing? (Watch for: transparent hosting recommendation, not lock-in to agency-managed hosting at marked-up prices.)
4. Pricing models and what they tell you
Fixed-fee, fixed-scope: best for marketing sites and well-defined builds. Quote should cover discovery, design, build, content migration, SEO migration, launch. Beware of fixed-fee quotes that exclude obvious work (content migration, third-party integrations, post-launch QA) because change requests will eat the savings.
Time and materials: appropriate for very large or evolving projects where scope cannot be locked in. Watch for: a clear rate card, expected hours estimate, weekly burn reports.
Monthly retainer: for ongoing work after launch (maintenance, optimisation, feature additions). Reasonable for clients who want continuous improvement; can become expensive if scope is not clearly defined.
Revenue share or performance-based: rare in web development. Often a sign the agency lacks confidence in upfront pricing or wants to lock the client in.
5. Red flags that should kill the deal
No live work you can browse. Templates of work but no recent live URLs. Senior salesperson but the people who will actually do the work are never named or shown. No clear answer on who owns the code (it should always be you). Pressure tactics on signing fast. Refusal to do a small paid trial or discovery project. Quotes that are dramatically lower than competitors (usually means scope cut or junior work). Aggressive monthly retainers presented as the only way to work with them. Reluctance to give you direct access to the developers during build.
6. Briefing the agency well
Briefs that get accurate quotes have: the type of site (marketing, SaaS, e-commerce, app), the target launch date, the budget range you are comfortable sharing (yes, share it; agencies budget within range), a list of the key pages or features you need, examples of sites or designs you like (3 to 5), information about your team's ongoing maintenance capability, and what success looks like (conversion rate, organic traffic, signups, etc.).
Do not over-specify the solution. Saying 'we want a Next.js site on Vercel with a Sanity CMS and Tailwind' before discovery limits the agency's ability to recommend the right stack for your use case. Saying 'we need a fast, maintainable, SEO-friendly marketing site that our marketing team can update without a developer' is better.
7. The contract checklist
Before signing, check the contract has: scope clearly defined with deliverables and acceptance criteria; payment schedule tied to milestones not just dates; IP ownership clause stating you own all code, design, and assets after final payment; change request process defined with how new work is quoted; defect warranty (typically 30 to 90 days post-launch where bugs in delivered scope are fixed at no charge); termination clause that lets you exit without losing what has been delivered; data and confidentiality terms appropriate for what they will access.
Key takeaways
- Be specific about what you are buying. Marketing site, SaaS site, e-commerce, web app, and platform are different products with different costs.
- Five questions: recent live work, named senior team, change request process, handover plan, why you over others.
- Stack should be chosen for your use case, not the agency's preference. Performance, SEO, accessibility baked in from day one.
- Fixed-fee for defined scope, T&M for evolving large projects. Watch for hidden exclusions in fixed-fee quotes.
- Red flags: no live URLs, anonymous teams, pressure tactics, agency owning the code, mandatory long retainers.
- Brief well: site type, launch date, budget range, key pages, design inspiration, team capability, success metrics.
- Contract must cover: scope, payment milestones, IP ownership, change process, defect warranty, exit terms.