How long does it take to build an app and what sets the date

How long does it take to build an app is a question with no single number, because the date is set by the pace of decisions, the availability of materials, and store review — not by the volume of code. The same set of features can take twice as long if sign-off on wireframes waits a week for a free slot in the board’s calendar. That is why the schedule below is broken into stages as percentages of the whole project: a percentage is immune to scale and works the same for an app with three screens and for one with thirty.

What the build time of an app depends on, and why one number does not exist

Four variables set the length of a project: the scope of the first release, the number of third-party integrations, how quickly you approve work, and what the app stores require. Only the first is fully in the hands of the development team, and even that one depends on how fast you close the feature list.

Ranges like “two weeks to three months” are useless, because they say nothing about where the risk of slippage sits. Deadlines rarely break during coding — they break while waiting: for a decision, for materials, for access to someone else’s API, for the outcome of a store review. Before you ask anyone for a date, close the scope of the first release, your MVP, because without it every date is guesswork.

The schedule in percentages: where the time actually goes

Splitting the schedule into shares of the whole shows risk better than a range in weeks, because the proportions between stages move more slowly than the total length of the project. The breakdown below is a model for a conversation with your development partner, not industry data — use it to ask how much the forgotten stages weigh in your project.

The proportion matters more here than the individual figures: programming itself takes roughly two fifths of the time. The rest is decisions, materials, testing, and procedures — the area where you, as the client, have the most influence. The full process of building a mobile app step by step is a separate subject; here only the clock matters.

The time nobody counts, because it is not programming

Most slippage comes from work that is not writing code and therefore never reaches an hourly estimate. It is worth listing explicitly before anyone quotes a launch date:

• Store review. Apple checks apps manually through App Review; Google Play relies more heavily on automated checks. A rejection means a fix and another round of review from the beginning.
• Sign-offs on your side. One unanswered decision about how a screen should look can stall an entire sprint, because the team will not build something that may still change.
• Collecting materials. Copy, product photos, terms of service, the privacy policy, and seed data for the database. That is your people’s work, not your development partner’s.
• Integrations that depend on a third party. API access, test accounts, rate limits, approvals, and signed data processing agreements. The provider’s procedure is sometimes longer than the implementation.
• Acceptance testing and the fixes that follow. Someone on your side has to actually click through the app, and the issues they raise come back to the team as extra work.
• Forced updates. Stores impose target API deadlines regardless of your scope, which is covered below.

Five things on your side that stretch the project

Each of these can be taken off the critical path by one decision made before the start, rather than during it.

1. A decision with no owner. Name one person with the right to approve wireframes and copy, by first and last name, and a deputy for the holiday season.
2. Approval by committee. Collect comments internally and hand the team one agreed list instead of contradictory notes from four people.
3. Materials “for later”. Give every content package a specific delivery date and an owner, exactly as you would a development task.
4. Credentials ordered at the last minute. Request API keys and test accounts during the architecture stage, not on the day integration work begins.
5. Scope changes mid-sprint. Put new ideas on the list for the next release; stopping a running sprint costs more than deferring a feature by two weeks.

The difference between a declaration and a commitment looks like this in practice:

If you want this sorted out before the first conversation, describe your project to our team — the more precisely you name the scope and who decides what, the sooner anyone can talk about a date at all.

Publishing: what really takes time in the App Store and Google Play

Publishing is a separate stage of the project with its own risk, not a formality you complete on the day you upload the build. Apple reviews apps manually, so the time is not guaranteed, and a rejection puts you back in the queue once you have applied the fixes. Google Play leans more on automated checks, but you still have to work through listing configuration, data declarations, and content policies. Avoiding that queue altogether is one reason teams look at a progressive web app installed straight from the browser — there is no store review to wait on, at the price of what iOS will not let a web app do.

On top of that come administrative procedures on the account owner’s side. Google may require developer identity verification — a job for your legal or finance people, not for the developers, and one you want closed well before launch.

Plan external testing separately. TestFlight lets you invite up to 10,000 testers from outside your organisation, but a build shared with that group goes through its own review at Apple. If you are planning a pilot with real users before launch, that is not one step but two passes through review.

Deadlines the stores impose regardless of your scope

Google Play requires that from 31 August 2026 new apps and updates target Android 16 (API 36) or higher, and that apps already published target at least Android 15 (API 35). In Play Console you can request an extension until 1 November 2026. That is work nobody ordered, but it has to fit into the plan if your project window covers that date.

The same mechanism runs every year and applies to apps you maintain after launch as well. When you budget for ongoing development — a subject covered alongside mobile app development cost — treat forced updates as a standing line item, not as an incident.

How to talk about a deadline so both sides know where they stand

Instead of asking “when will it be ready”, ask three things: what scope fits inside that date, which stages depend on your decisions, and what happens to the date when a sign-off arrives a week late. Answers to those questions can be verified; a date quoted without them cannot.

Work usually runs in two-week sprints, and the review at the end of a sprint is the natural moment for partial sign-off — that is when you see whether the proportions from the table still hold. A typical team is a project manager, an analyst, a UX/UI designer, iOS, Android, and backend developers, and QA; the more roles have to wait on one decision of yours, the more expensive every day of delay becomes. Keep the order of the stages of app development in front of you from the first conversation about a date, because it shows where your own tasks fall in the calendar — and which features you can move out of the scope of the first release when the calendar gets tight.