Custom web application development, priced before we start

If you run a growing business or a startup and need custom web application development without an agency budget, we build web apps with accounts, data, payments and an admin panel for $6,900 (Core) or $11,900 (Plus), fixed price, in 2 to 4 weeks. A working preview appears within 5 business days of the deposit, or you get the deposit back. AI agents write the code and one senior engineer verifies every delivery.

This page is for businesses with a process to digitize or a product to offer customers: a client portal, a booking system, a membership platform, a quoting tool. If you are a founder testing a product idea with early users, see MVP development services, which shares the same packages but a different journey. If your users are your own staff, an internal tool may fit better and start at $4,500.

What is included

Core ($6,900): up to 6 main screens, login, a database, Stripe payments and an admin panel.

Plus ($11,900): up to 12 screens, 2 third-party integrations, one AI feature, analytics and onboarding emails.

Both include a staging demo, production deployment to your accounts and 2 revision rounds per milestone. Your private GitHub repository exists from the first day, and the guarantee covers a 30-day bug warranty after launch.

What is not included

• Native mobile apps. The web app is responsive and works on phones, but app store apps are a separate mobile package.
• Screens, integrations or roles beyond the scope sheet. We quote them before building.
• Data migration from complex legacy systems. Simple imports are fine. Messy sources need a scoping conversation first.
• Hosting, domain and API fees. These sit on your accounts and bills.
• Marketing sites with many pages. Those are better served by the Launch Site package.

How we compare

	Tantito	Typical agency	Freelancer marketplace
Price	$6,900 to $11,900 fixed	$25,000 to $150,000 at $100 to $130 per hour in the US	$3,000 to $15,000, often at the low end
Timeline	2 to 4 weeks	3 to 6 months	4 to 12 weeks, depending on availability
Code ownership	Yours from day one, in your GitHub	Usually transferred at final payment	Depends on the contract
Guarantee	Preview in 5 business days or deposit back, 30-day warranty	Rarely any	Platform dispute process only

How a web app build runs

1. Day 0: Deposit, then a one-page scope sheet listing every screen, role and integration.
2. Days 1 to 5: We deliver a preview with the data model and the first working flow, using realistic sample data.
3. Weeks 2 and 3: Remaining screens, roles, payments and integrations. You review at each milestone.
4. Final week: Staging demo, test and security pass, import of your existing data, then launch on your accounts.

Projects of $3,000 and up pay 30% at the start, 40% at the staging demo and 30% at launch. How we work has the details.

Example web apps this package fits

• For example, a client portal for an accounting or consulting firm where customers log in, upload documents, see project status and pay invoices.
• For example, a booking and membership platform for a fitness studio with class capacity, recurring Stripe payments and an admin schedule.
• For example, a quoting and ordering app for a wholesale distributor, with per-customer price lists and PDF quotes.
• For example, a Plus-tier training platform with course progress tracking, onboarding emails and an AI feature that answers learners’ questions from the lesson content.

These are illustrations of scope, not past client work.

Technology we typically use

Defaults are TypeScript, Next.js, Postgres (often on Supabase, with row-level security), Stripe for payments, transactional email, and OpenAI or Anthropic APIs for AI features. Hosting runs on Vercel or a similar provider in your account. These are defaults, not requirements, and we adapt to existing infrastructure.

How “AI-built, human-verified” applies to a web app

AI agents write screens, forms and API routes quickly, which is why a web app costs thousands, not tens of thousands. A senior engineer then reviews the code before delivery, with particular attention to what AI-generated code often gets wrong: authorization checks on every route, row-level access rules, payment webhooks, input validation and secrets handling. Automated tests cover the main flows, and a dependency and security scan runs before launch. You get a short report with what was checked.

The main objection: why custom instead of no-code or off-the-shelf software?

Sometimes you should not go custom, and we say so. If a tool such as a standard booking or CRM product covers 90% of your needs at a fair monthly fee, use it. Custom wins in three cases: your workflow is a competitive advantage that tools force you to bend, per-seat pricing grows faster than your revenue, or you have hit limits in permissions, data volume or integrations. A fixed-price build also turns the monthly fee into an asset you own. Our custom software development cost guide walks through the comparison with numbers.

When this is not the right fit

Custom is a poor choice if your requirements change weekly and you have not tested the workflow on paper, because every change is a decision you pay for. It is also unnecessary when a mature product already does the job. For apps that must handle very large traffic, strict regulatory audits or complex multi-tenant billing from launch, a fixed price at this level will not cover the engineering, and we will recommend a scoping phase first.

Next steps

Browse the pricing page, run a rough estimate in the software cost calculator, or request a web app quote. To understand why fixed pricing changes the risk, read fixed price versus hourly software development.