Bury St Edmunds · 01284 766290
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January 30th, 2026 · Jabu_ Team

How long does it take to build a custom web app?

"How long will it take?" is the second question we always get after "how much will it cost?". Here's the honest answer — and what determines whether your project lands at the fast end or the slow end of the range.

Web application project timeline displayed on screens

The headline numbers

Across hundreds of web application development projects we've delivered for Suffolk and UK businesses, the timelines look like this:

What actually drives the timeline

Three things determine where your project falls in those ranges:

1. How well-defined the requirements are at kickoff

If you arrive with a clear specification, agreed user flows, and stakeholders who know what they want, the project moves fast. If we're discovering requirements as we go, every week of decision-making delay extends the build.

2. How many integrations are needed

A standalone web app is faster than one that needs to talk to Xero, Stripe, HubSpot, and a custom legacy system. Each integration is a project of its own, with its own discovery, testing, and edge cases.

3. The complexity of business logic

"Show users a list of products" is fast. "Calculate dynamic pricing based on user role, product variants, regional tax, volume discounts, and seasonal promotions" is much slower. The visible UI of an app is often only 30% of the work — the rest is logic you don't see.

How we structure the timeline

Every web app project we deliver runs on the same five phases:

Why faster isn't always better

Some agencies promise to deliver in half the time we'd quote. There are three places that time usually comes from, and none of them are good:

How to make your project finish faster

There are three things you can do as a client that genuinely speed things up:

Ready to talk?

If anything in this article rings true for your business, we'd love to chat. We offer free initial consultations for all Suffolk businesses.

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Frequently asked questions

An extremely simple internal tool, sometimes. A genuine product that users will rely on, no — not without compromising quality. The minimum we'd recommend for anything customer-facing is 8-10 weeks.
Almost always client-side decisions and content. Development time is generally predictable; client review cycles often aren't.
Agile, with 2-week sprints. We share working software at the end of each sprint and adjust priorities based on what you see.

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