How to Build Your Own OnPay
Replace OnPay with a custom build. Top-Rated Payroll Services, HR and More
Build Difficulty: 5/5
Build a working replacement in a weekend with AI tools
Estimated Timeline
Based on 44 features at Weekend Project difficulty, expect about One weekend with AI-assisted development.
Recommended Tech Stack
Full-stack React framework with API routes and server components
PostgreSQL database, auth, and real-time subscriptions
Utility-first styling for rapid UI development
Type-safe ORM for complex relational data models
Key Features to Replicate
Top features across 8 categories. See all 44 features
Benefits(9 features)
Add-on life, vision, disability, and other insurance types with in-house licensed brokers
Automatic premium deduction and policy updates for employee team changes during payroll runs
Integration with existing benefits provider and plans through broker of record integration
Partnership with top providers to offer low-fee 401(k) plans with great investment options
Fully integrated workers' comp administration using payroll data with automatic premium deduction
+4 more in this category
Payroll(9 features)
Automatic withholding of federal, state, and local payroll taxes, filing of Form 941 quarterly and Form 940 annually
Pay employees via direct deposit with no extra fees
Automatic deduction and tracking of garnishments with customizable rules and goals
Run payroll and handle taxes for employees in multiple states with no extra fees across all 50 states
Set multiple pay schedules and different pay rates for individual employees without extra fees
+4 more in this category
HR(8 features)
New employees self-onboard, e-sign HR documents, and complete profiles online with automated task assignment for team members
Customizable document templates with ability to import custom docs or access HR library
Create customizable checklists for specific events or employee types including documents and task assignments
Upload any HR document for e-signing or use built-in e-signable templates
Access to hundreds of HR guides and legal templates within the platform
+3 more in this category
PTO Management(5 features)
Automatic calculation and addition of PTO hours to employee totals with each payroll run
Create paid time off policies based on multiple criteria for flexibility
Employees can request PTO through dashboard with manager approval workflow and automatic deduction
Set up to 3 accrual tiers allowing employees to earn PTO at different rates based on type, location, or seniority
Visual calendar showing upcoming employee PTO days with email notifications for managers and admins
Org Charts(4 features)
Org chart automatically updates when employees modify their profiles
Employee profiles including name, title, company contact info, org chart position, personal contact, pictures, and fun facts
Automatically generated directory accessible to all employees for easy communication
Interactive org chart showing company hierarchy with ability to zoom and view specific departments
Compliance(2 features)
Review personnel checklists and receive alerts for outdated documents or incomplete tasks
Automatic reporting of new hires to state agencies when employees set up their OnPay accounts
Authentication(1 features)
Streamline access using Google, Intuit, or Xero login credentials
Communication(1 features)
In-app messaging between employees, managers, and admins with automatic storage and paper trail
Cost Calculator
Keep Paying OnPay
Build It Yourself
Total Cost Comparison
DIY hosting estimate based on Vercel + Supabase free/pro tiers (~$20/mo). Build time estimated from 44 features at very easy complexity.