How long does it take to build an app?
Building an app typically takes between three and twelve months depending on complexity, team size, and how clearly the scope is defined before development starts.
Industry data is consistent on the ranges. Simple apps with basic functionality take three to four months. Mid-complexity apps with multiple features and integrations typically take four to nine months. Complex apps with custom backends, AI features, or enterprise integrations regularly take nine to twelve months or longer.
But those ranges assume a clear brief. 78% of software projects experience scope creep, and every undefined requirement at the start becomes a decision, a delay, and usually an additional cost during the build. Projects with poorly defined requirements consistently run over time and over budget.
What used to be unavoidable is now fixable before development starts. A working prototype (built in days, tested with real users, refined based on what you learn) defines the scope precisely enough that development estimates become reliable rather than aspirational. The timelines above are real. How much of that time gets spent building the wrong thing depends entirely on the clarity you go in with.
Read our full guide to app development costs and timelines in the UK →